catalogo brossard parafusos

8/13/2019 Catalogo Brossard Parafusos

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Technical information


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Materials screws & nuts T.002De nitions of mechanical propertiesfor screws T.002

ScrewsProperty class 4.6 to 12.9 T.004

NutsProperty class 04 to 12 T.009

Set screwsProperty class 14 H to 45 H T.012

Screws, bolts, nuts T.013

Screws and nutsfor high and low temperatures T.016

Stainless steel fasteners T.020

Fasteners of various materials T.026

Corrosion protection T.031

Arrangement, design, assembly T.034

Selection of fasteners T.034

Fatigue resistance T.035

Length of engaged thread T.036

Surface pressure when mounted T.037

Friction and friction coe cients T.041

Tightening method, tightening factor A T.042

Preload and tightening torques T.044

Securely fastened connections T.055

Shear loads for pins T.058

Construction recommendations T.059

Assembly tools T.072

frompage

Metric ISO threads T.074

Tolerances, tables, standards T.077

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Materials screws & nuts

De nitions of mechanical properties for screws


Tensile strength R m [N/mm 2]Determines how much stress a screw must withstand withoutbreaking. If full size screws are tested, the yield strengthcan only be approximately established. Under ISO 898 Part 1, theexact yield strength and elongation after fracture can be deter-mined using machined specimens. Exceptions are stainlesssteel screws A1 to A4 (ISO 3506).

Tensile strength at rupture in thread:

Rm = max. tensile force F N stress area mm2

Tensile strength at rupture in cylindrical shank:

Rm = max. tensile force F Ninitial cross section of specimen mm2

F

Tensile test onfull size screw

Yield strength R eL [N/mm 2]Yield strength is the amount of resistance of a material to plasticdeformation. In general terms, yield strength determines howmuch stress a screw (specimen) must withstand without being

permanently elongated. This applies to relatively soft materials.

elongation

t e n s

i l e f o r c e

m a x .

t e n s

i l e f o r c e

y i e l d p o

i n t

0,2 % limit R p0,2 [N/mm 2]The yield point of somewhat harder materials is not sharply pro-nounced. It is then replaced by the stress at which the permanentelongation is 0.2 %.In practice, screws may be stressed by tightening and underwork-ing load no more than up to the yield strength or the 0,2 limit.

elongation

t e n s

i l e f o r c e

m a x .

t e n s

i l e f o r c e

l i m i t R

p 0

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Tensile teston machinedscrew

Stress area As [mm2] of thread Pages T.038, T.039

1 N/mm 2 = 1 MPa = 145.03 psi


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Elongation at fracture A [%]is the permanent elongation measured on the fractured specimenrelated to the original measured length. Exceptions: screwsA1 to A4, where this is measured on fullsize screws (ISO 3506).

d o

Lo = 5 x d o

measuringlength

Tensile strength under wedge loadingIs tested by means of having a wedge positioned underneath thescrew head. When tensioned, the screw must break in the threador in the shank. Bolts and screws are subjected to a wedge test tomeasure the ductility and head integrity.

Head soundnessThe head of the screw must withstand several hammer blows.After being bent to a specified angle, the shank head fillet shall

not show any signs of cracking. For details see ISO 898, part 1.

Notch Impact Strength [Joule] ISO 83Notch impact energy is the impact energy consumed duringnotch impact testing. A notched sample is taken from the screwnear the surface. This sample is broken in a pendulum impacttester with a single stroke. It gives information on micro-structure,steel making process, inclusion content etc. The values cannotbe used for calculations.

Surface FlawsSurface defects arising in the semi-finished product are slaginclusions, material folds and die marks.Cracks on the otherhand are crystalline breaks without inclusion of foreign materials.For details see EN 493 and ISO 6157.

DecarburizationDecarburization is a loss of carbon at the surface of ferrousmaterials (steels). For details see ISO 898, part 1.

F



HardnessHardness is generally the resistance of the material to penetrationby a test body. The advantage of the Vickers hardness test is thatthe entire hardness range encountered in the screw is covered bythe method. For details see ISO 898, part 1.

Vickers hardness HV: ISO 6507Test body-pyramid(encompasses the complete hardness range usual for screws)

Brinell hardness HB: ISO 6506Test body ball

Rockwell hardness HRC: ISO 6508Test body cone

Hardness comparison tables Page T.082



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Screws Property class 4.6 to 12.9/12.9

Mechanical and physical properties of screws

according to ISO 898, part 1

The mechanical properties are given for tests at room temperature.

No. Mechanical or physical property Property class4.6 4.8 5.6 5.8 6.8 8.8 9.8 10.9 12.9/

12.9d 16 d > 16 d 16mma mmb mm

1 Tensile strength, Rm, MPa, [N/mm2] nom.c 400 400 500 500 600 800 800 900 1 000 1 200min. 400 420 500 520 600 800 830 900 1 040 1 220

2 Lower yield strength, ReLd, MPa, [N/mm2] nom.c 240 300 min. 240 300

3 Stress at 0,2 % non-proportional elongationRp0,2, MPa, [N/mm2]

nom.c 640 640 720 900 1080min. 640 660 720 940 1 100

4 Stress at 0,0048 d non-proportional elongationfor full-size fasteners Rpf, MPa, [N/mm2]

nom.c 320 400 480 min. 340e 420e 480e

5 Stress under proof load, Spf, MPa, [N/mm2] nom. 225 310 280 380 440 580 600 650 830 970

Proof strength ratio

Sp, nom /ReL min or 0,94 0,91 0,93 0,90 0,92 0,91 0,91 0,90 0,88 0,88Sp, nom /Rp0,2 min orSp, nom /Rpf min

6 Percentage elongation after fracture for machinedtest pieces, A, %

min. 22 20 12 12 10 9 8

7 Percentage reduction of area afterfracture for machined test pieces, Z, %

min. 52 52 48 48 44

8 Elongation after fracture for full-size fasteners, Af(see also ISO 898-1 Annex C)

min. 0,24 0,22 0,20

9 Head soundness no fracture10 Vickers hardness, HV

F 98 Nmin. 120 130 155 160 190 250 255 290 320 385max. 220g 220g 220g 220g 250 320 335 360 380 435

11 Brinell hardness, HBWF = 30D2

min. 114 124 147 152 181 238 242 276 304 366max. 209g 209g 209g 209g 238 304 318 342 361 414

12 Rockwell hardness, HRB min. 67 71 79 82 89 max. 95,0g 95,0g 95,0g 95,0g 99,5 Rockwell hardness, HRC min. 22 23 28 32 39

max. 32 34 37 39 4413 Surface hardness, HV 0,3 max. h h h h, i h, j14 Height of non-decarburized thread zone,

E, mmmin. 1 / 2 H1 1 / 2 H1 1 / 2 H1 2 / 3 H1 3 / 4 H1

Depth of complete decarburization in the thread,G, mm

max. 0,015 0,015 0,015 0,015 0,015

15 Reduction of hardness after retempering, HV max. 20 20 20 20 2016 Breaking torque,MB Nm min. in accordance with ISO 898-717 Impact strength Kvk, l, J min. 27 27 27 27 27 m

18 Surface integrity in accordance withISO 6157-1n ISO

6157-3a Values do not apply for structural bolting.b For structural bolting d M12.c Nominal values are speci ed only for the purpose of the desigation system for property classes. See clause 5.d In cases where the lower yield strength ReLcannot be determined, it is permissible to measure the stress at 0,2 % non-proportional elongation Rp0,2.e For the property classes 4.8, 5.8 and 6.8 the values for Rpf min are under investigation. The present values are given for calculation of the proof stress ratio

only. They are not test values.f Proof loads are speci ed in tables T.006.g Hardness determined at the end of a fastener shall be 250 HV, 238 HB or 99,5 HRB maximum.h Surface hardness shall not be more than 30 Vickers points above the measured core hardness of the fastener when determination of both surface hardness

and core hardness are carried out with HV 0,3.i Any increase in hardness at the surface which indicates that the surface hardness exceeds 390 HV is not acceptable. j Any increase in hardness at the surface which indicates that the surface hardness exceeds 435 HV is not acceptable.k Values are determined at a test temperature of 20 C.l Applies to d 16 mm.m

Value for KV is under investigation.n Instead of ISO 6157-1, ISO 6157-3 may apply by agreement between the manufacturer and the purchaser.



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Minimum ultimate tensile loads


Minimum ultimate tensile loads ISO metric coarse pitch thread

Thread1)d Nominalstress areaAs, nom[mm2]

Minimum ultimate tensile load Fm min (As, nom xRm, min) [ N ]Property class4.6 4.8 5.6 5.8 6.8 8.8 9.8 10.9 12.9/12.9

M3 5,03 2 010 2 110 2 510 2 620 3 020 4 020 4 530 5 230 6 140M3,5 6,78 2 710 2 850 3 390 3 530 4 070 5 420 6 100 7 050 8 270M4 8,78 3 510 3 690 4 390 4 570 5 270 7 020 7 900 9 130 10 700M5 14,2 5 680 5 960 7 100 7 380 8 520 11 350 12 800 14 800 17 300M6 20,1 8 040 8 440 10 000 10 400 12 100 16 100 18 100 20 900 24 500M7 28,9 11 600 12 100 14 400 15 000 17 300 23 100 26 000 30 100 35 300M8 36,6 14 6002) 15 400 18 3002) 19 000 22 000 29 2002) 32 900 38 1002) 44 600M10 58,0 23 2002) 24 400 29 0002) 30 200 34 800 46 4002) 52 200 60 3002) 70 800M12 84,3 33 700 35 400 42 200 43 800 50 600 67 4003) 75 900 87 700 103 000M14 115 46 000 48 300 57 500 59 800 69 000 92 0003) 104 000 120 000 140 000

M16 157 62 800 65 900 78 500 81 600 94 000 125 0003) 141 000 163 000 192 000M18 192 76 800 80 600 96 000 99 800 115 000 159 000 200 000 234 000M20 245 98 000 103 000 122 000 127 000 147 000 203 000 255 000 299 000M22 303 121 000 127 000 152 000 158 000 182 000 252 000 315 000 370 000M24 353 141 000 148 000 176 000 184 000 212 000 293 000 367 000 431 000M27 459 184 000 193 000 230 000 239 000 275 000 381 000 477 000 560 000M30 561 224 000 236 000 280 000 292 000 337 000 466 000 583 000 684 000M33 694 278 000 292 000 347 000 361 000 416 000 576 000 722 000 847 000M36 817 327 000 343 000 408 000 425 000 490 000 678 000 850 000 997 000M39 976 390 000 410 000 488 000 508 000 586 000 810 000 1 020 000 1 200 000

1) Where no thread pitch is indicated in a thread designation, coarse pitch is specified.2) For fasteners with thread tolerance 6az according to ISO 965-4 subject to hot dip galvanizing, reduced values in accordance with ISO 10684.3) For structural bolting 70 000 N (for M12), 95 500 N (for M14) and 130 000 N (for M16).

Minimum ultimate tensile loads ISO metric fine pitch thread

Threadd x P

Nominalstress areaAs, nom[mm2]

Minimum ultimate tensile load Fm min (As, nom xRm, min) [ N ]

Property class4.6 4.8 5.6 5.8 6.8 8.8 9.8 10.9 12.9/12.9

M8 x 1 39,2 15 700 16 500 19 600 20 400 23 500 31 360 35 300 40 800 47 800M10 x 1 64,5 25 800 27 100 32 300 33 500 38 700 51 600 58 100 67 100 78 700M10 x 1,25 61,2 24 500 25 700 30 600 31 800 36 700 49 000 55 100 63 600 74 700M12 x 1,25 92,1 36 800 38 700 46 100 47 900 55 300 73 700 82 900 95 800 112 000M12 x 1,5 88,1 35 200 37 000 44 100 45 800 52 900 70 500 79 300 91 600 107 000M14 x 1,5 125 50 000 52 500 62 500 65 000 75 000 100 000 112 000 130 000 152 000M16 x 1,5 167 66 800 70 100 83 500 86 800 100 000 134 000 150 000 174 000 204 000M18 x 1,5 216 86 400 90 700 108 000 112 000 130 000 179 000 225 000 264 000M20 x 1,5 272 109 000 114 000 136 000 141 000 163 000 226 000 283 000 332 000M22 x 1,5 333 133 000 140 000 166 000 173 000 200 000 276 000 346 000 406 000M24 x 2 384 154 000 161 000 192 000 200 000 230 000 319 000 399 000 469 000M27 x 2 496 198 000 208 000 248 000 258 000 298 000 412 000 516 000 605 000M30 x 2 621 248 000 261 000 310 000 323 000 373 000 515 000 646 000 758 000M33 x 2 761 304 000 320 000 380 000 396 000 457 000 632 000 791 000 928 000M36 x 3 865 346 000 363 000 432 000 450 000 519 000 718 000 900 000 1 055 000M39 x 3 1 030 412 000 433 000 515 000 536 000 618 000 855 000 1 070 000 1 260 000

To calculate the nominal stress areaAs, nom Page T.038



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Proof loads of screws


Proof loads ISO metric coarse pitch thread

Thread1)d

Nominalstress areaAs, nom [ mm2]

Proof load Fp (As, nom x Sp, nom) [ N ]Property class4.6 4.8 5.6 5.8 6.8 8.8 9.8 10.9 12.9/12.9

M3 5,03 1 130 1 560 1 410 1 910 2 210 2 920 3 270 4 180 4 880M3,5 6,78 1 530 2 100 1 900 2 580 2 980 3 940 4 410 5 630 6 580M4 8,78 1 980 2 720 2 460 3 340 3 860 5 100 5 710 7 290 8 520M5 14,2 3 200 4 400 3 980 5 400 6 250 8 230 9 230 11 800 13 800M6 20,1 4 520 6 230 5 630 7 640 8 840 11 600 13 100 16 700 19 500M7 28,9 6 500 8 960 8 090 11 000 12 700 16 800 18 800 24 000 28 000M8 36,6 8 2402) 11 400 10 2002) 13 900 16 100 21 2002) 23 800 30 4002) 35 500M10 58,0 13 0002) 18 000 16 2002) 22 000 25 500 33 7002) 37 700 48 1002) 56 300M12 84,3 19 000 26 100 23 600 32 000 37 100 48 9003) 54 800 70 000 81 800M14 115 25 900 35 600 32 200 43 700 50 600 66 7003) 74 800 95 500 112 000M16 157 35 300 48 700 44 000 59 700 69 100 91 0003) 102 000 130 000 152 000M18 192 43 200 59 500 53 800 73 000 84 500 115 000 159 000 186 000M20 245 55 100 76 000 68 600 93 100 108 000 147 000 203 000 238 000M22 303 68 200 93 900 84 800 115 000 133 000 182 000 252 000 294 000M24 353 79 400 109 000 98 800 134 000 155 000 212 000 293 000 342 000M27 459 103 000 142 000 128 000 174 000 202 000 275 000 381 000 445 000M30 561 126 000 174 000 157 000 213 000 247 000 337 000 466 000 544 000M33 694 156 000 215 000 194 000 264 000 305 000 416 000 576 000 673 000M36 817 184 000 253 000 229 000 310 000 359 000 490 000 678 000 792 000M39 976 220 000 303 000 273 000 371 000 429 000 586 000 810 000 947 000

1) Where no thread pitch is indicated in a thread designation, coarse pitch is specified.2) For fasteners with thread tolerance 6az according to ISO 965-4 subject to hot dip galvanizing, reduced values in accordance with ISO 10684.3) For structural bolting 50 700 N (for M12), 68 800 N (for M14) and 94 500 N (for M16).

Proof loads ISO metric fine pitch thread

Thread d x P

Nominalstress areaAs, nom[ mm2]

Proof load Fp (As, nom x Sp, nom) [ N ]

Property class4.6 4.8 5.6 5.8 6.8 8.8 9.8 10.9 12.9/12.9

M8 x 1 39,2 8 820 12 200 11 000 14 900 17 200 22 700 25 500 32 500 38 000M10 x 1,25 61,2 13 800 19 000 17 100 23 300 26 900 35 500 39 800 50 800 59 400M10 x 1 64,5 14 500 20 000 18 100 24 500 28 400 37 400 41 900 53 500 62 700M12 x 1,25 92,1 20 700 28 600 25 800 35 000 40 500 53 400 59 900 76 400 89 300M12 x 1,5 88,1 19 800 27 300 24 700 33 500 38 800 51 100 57 300 73 100 85 500M14 x 1,5 125 28 100 38 800 35 000 47 500 55 000 72 500 81 200 104 000121 000M16 x 1,5 167 37 600 51 800 46 800 63 500 73 500 96 900 109 000 139 000162 000M18 x 1,5 216 48 600 67 000 60 500 82 100 95 000 130 000 179 000 210 000M20 x 1,5 272 61 200 84 300 76 200 103 000 120 000 163 000 226 000 264 000M22 x 1,5 333 74 900 103 000 93 200 126 000 146 000 200 000 276 000 323 000M24 x 2 384 86 400 119 000 108 000 146 000 169 000 230 000 319 000 372 000M27 x 2 496 112 000 154 000 139 000 188 000 218 000 298 000 412 000 481 000M30 x 2 621 140 000 192 000 174 000 236 000 273 000 373 000 515 000 602 000M33 x 2 761 171 000 236 000 213 000 289 000 335 000 457 000 632 000 738 000M36 x 3 865 195 000 268 000 242 000 329 000 381 000 519 000 718 000 839 000M39 x 3 1 030 232 000 319 000 288 000 391 000 453 000 618 000 855 000 999 000

To calculate the nominal stress areaAs, nom Page T.038





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Materials, heat treatment, chemical compositions


Steels

Propertyclass

Material and heat treatment Chemical composition limits(cast analysis, %)1)Temperingtemperature

C P S B2) C

min. max. max. max. max. min.4.63), 4) Carbon steel or carbon steel with additives 0,55 0,05 0,06 not

specified

4.84)

5.63) 0,13 0,55 0,05 0,065.84) 0,55 0,05 0,066.84) 0,15 0,55 0,05 0,068.86) Carbon steel with additives (e.g. Boron or Mn or Cr),

quenched and tempered0,155) 0,40 0,025 0,025 0,003 425

or 0,25 0,55 0,025 0,025Carbon steel, quenched and temperedor 0,20 0,55 0,025 0,025Alloyed steel, quenched and tempered7)

9.86) Carbon steel with additives (e.g. Boron or Mn or Cr),quenched and tempered

0,155) 0,40 0,025 0,025 0,003 425

or 0,25 0,55 0,025 0,025Carbon steel, quenched and temperedor 0,20 0,55 0,025 0,025Alloyed steel, quenched and tempered7)

10.96) Carbon steel with additives (e.g. Boron, Mn oder Cr), quenched and tempered

0,205) 0,55 0,025 0,025 0,003 425

or 0,25 0,55 0,025 0,025Carbon steel, quenched and tempered

or 0,20 0,55 0,025 0,025Alloyed steel, quenched and tempered7)

12.96), 8), 9) Alloyed steel, quenched and tempered7) 0,30 0,50 0,025 0,025 0,003 42512.96), 8), 9) Carbon steel with additives (e.g. Boron, Mn or Cr or

Molybdenum), quenched and tempered0,28 0,50 0,025 0,025 0,003 380

1) In case of dispute, the product analysis applies.2) Boron content can reach 0,005 %, provided that non-effective boron is controlled by addition of titanium and/or aluminium.3) For cold forged fasteners of property classes 4.6 and 5.6, heat treatment of the wire used for cold forging or of the cold forged fastener itself may be

necessary to achieve required ductility.4) Free cutting steel is allowed for these property classes with the following maximum sulphur, phosphorus and lead contents: sulphur 0,34 %; phosphorus

0,11 %; lead 0,35 %.5) In case of plain carbon boron steel with a carbon content below 0,25 % (cast analysis), the minimum manganese content shall be 0,6 % for property class 8.8

and 0,7 % for 9.8 and 10.9.6) For the materials of these property classes, there shall be a sufficient hardenabiltity to ensure a structure consisting of approximately 90 % martensite in the

core of the threaded sections for the fasteners in the "as-hardened" condition before tempering.7) This alloy steel shall contain at least one of the following elements in the minimum quantity given: chromium 0,3 %, nickel 0,3 %, molybdenum 0,2 %,vanadium 0,1 %. Where elements are specified in combinations of two, three or four and have alloy contents less than those given above, the limit value tobe applied for class determination is 70 % of the sum of the individual limit values shown above for the two, three or four elements concerned.

8) A metallographically detectable white phosphorous enriched layer is not permitted for property class 12.9/12.9. It shall be detected by a suitable test method.9) Caution is advised when the use of property class 12.9/12.9 is considered. The capability of the fastener manufacturer, the service conditions and the

wrenching methods should be considered. Environments may cause stress corrosion cracking of fasterners as processed as well as those coated.





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In uence of elevated temperatures on mechanicalproperties of fastenersElevated temperatures can cause changes in the mechanicalproperties and in the functional performance of a fastener.

Up to typical service temperatures of 150 C, no detrimentaleffects due to a change of mechanical properties of fastenersare known. At temperatures over 150 C and up to a maximumtemperature of 300 C, the functional performance of fastenersshould be ensured by careful examination.

With encreasing temperatures, a progressive reduction of lower yield strength or stress at 0,2 % non-propor-tional elongation or stress at 0,0048 d non-proportional elongation for finished fasteners, and reduction of tensile strength can be experienced. The continu-ous operating of fasteners at elevated service temperatures canresult in stress relaxation, which increases with higher tempera-tures. Stress relaxation accompanies a loss of clamp force.

Work-hardened fasteners (property classes 4.8, 5.8, 6.8) aremore sensitive with regard to stress relaxation compared withquenched and tempered or stress-relieved fasteners.

Care should be taken when lead-containing steels are used forfasteners at elevated temperatures. For such fasteners, a risk ofliquid metal embrittlement (LME) should be taken into consider-ation when the service temperature is in the range of the meltingpoint of lead.

Information for example, in EN 10269 and in ASTM F2281.

Influence of higher screw property class under comprehension of the mechanical stress and environmental conditions.

High-strength material

Brittling of material stress corrosion cracking hydrogen embrittlement

Mechanical fracture forced fracture fatigue fracture shear fracture cleavage fracture mixed fracture oscillating fracture

Erosion corrosion uniform corrosion pitting corrosion crevice corrosion galvanic corrosion

Ambient medium e.g. hydrogen, acid rain

Mechanical stress

Risk of hydrogen embrittlementPage T.031

Characteristics at elevated temperatures


Characteristics at higher strength (if 1000 N/mm 2)





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Mechanical properties of nuts with ISO metric threads (coarse)

according to ISO 898, part 2Property class

Thread-to M4 > M4 to M7 > M7 to M10 > M10 to M16 > M16 to M39

04 Stress under proof load, Sp, [N/mm2] 380 380 380 380 380Vickers hardness HV min. 188 188 188 188 188

max. 302 302 302 302 30205 Stress under proof load, Sp, [N/mm2] 500 500 500 500 500

Vickers hardness HV min. 272 272 272 272 272max. 353 353 353 353 353

4 Stress under proof load, Sp, [N/mm2] 510Vickers hardness HV min. 117

max. 3025 Stress under proof load, Sp, [N/mm2] 520 580 590 610 630


6 Stress under proof load, Sp, [N/mm2] 600 670 680 700 720

Vickers hardness HV min. 150 150 150 150 170max. 302 302 302 302 30283) Stress under proof load, Sp, [N/mm2] 800 855 870 880 920


9 Stress under proof load, Sp, [N/mm2] 900 915 940 950 920Vickers hardness HV min. 170 188 188 188 188

max. 302 302 302 302 30210 Stress under proof load, Sp, [N/mm2] 1 040 1 040 1 040 1 050 1 060


121) Stress under proof load, Sp, [N/mm2] 1 140 1 140 1 140 1 170 Vickers hardness HV min. 295 295 295 295

max. 353 353 353 353

122)

Stress under proof load, Sp, [N/mm2] 1 150 1 150 1 160 1 190 1 200Vickers hardness HV min. 272 272 272 272 272

max. 353 353 353 353 353 1) Nuts style 1 (ISO 4032) 0,9 d nuts2) Nuts style 2 (ISO 4033) 1,0 d nuts3) Class 8 M16 only type 1 (not heat-treated) > M16 type 1 (hardened and tempered) and type 2 (not heat-treated)

Property class Nuts Thread05 to 8 Type1 metric ISO thread > M1605 to 8 Type1 ne pitch thread10 and 12 metric ISO thread

ne pitch thread

The mechanical properties as listed apply to heat-treated nuts: Notes

The minimum hardness values are binding only for nuts forwhich a test stress measurement can not be performed andfor heat treated nuts. The minimum values are guidelines for

all other nuts. The minimum hardness values for nuts with nominal threaddiameters above 39 and to 100 mm are for information onlyand are considered reference values.


Nuts Property classes 04 to 12



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The standard values for strip resistance relate to the given boltclasses. The exterior thread may be expected to strip if the nutsare paired with screws of lover property classes, while the threadof the nut will strip if it is paired with screws of higher propertyclasses.

Propertyclass of

nut

Proof loadstress

of the nut[N/mm2]

Minimum stress in the core of bolt whenstripping occurs for bolts with property class

[N/mm2]

6.8 8.8 10.9 12.904 380 260 300 330 35005 500 290 370 410 480

Thread1) Nominal stressarea of thematerial AS[mm2]

Test load (AS x Sp), [ N ]Property class04 05 4 5 6 8 9 10 12 Style 1 Style 1 Style 1 Style 1 Style 2 Style 2 Style 2 Style 2 Style 2

M3 5,03 1 910 2 500 2 600 3 000 4 000 4 500 5 200 5 700 5 800M3,5 6,78 2 580 3 400 3 550 4 050 5 400 6 100 7 050 7 700 7 800M4 8,78 3 340 4 400 4 550 5 250 7 000 7 900 9 150 10 000 10 100M5 14,2 5 400 7 100 8 250 9 500 12 140 13 000 14 800 16 200 16 300M6 20,1 7 640 10 000 11 700 13 500 17 200 18 400 20 900 22 900 23 100M7 28,9 11 000 14 500 16 800 19 400 24 700 26 400 30 100 32 900 33 200M8 36,6 13 900 18 300 21 600 24 900 31 800 34 400 38 100 41 700 42 500M10 58,0 22 000 29 000 34 200 39 400 50 500 54 500 60 300 66 100 67 300M12 84,3 32 000 42 200 51 400 59 000 74 200 80 100 88 500 98 600 100 300M14 115 43 700 57 500 70 200 80 500 101 200 109 300 120 800 134 600 136 900M16 157 59 700 78 500 95 800 109 900 138 200 149 200 164 900 183 700 186 800M18 192 73 000 96 000 97 900 121 000 138 200 176 600 170 900 176 600 203 500 230 400M20 245 93 100 122 500 125 000 154 000 176 400 225 400 218 100 225 400 259 700 294 000M22 303 115 100 151 500 154 500 190 900 218 200 278 800 269 700 278 800 321 200 363 600M24 353 134 100 176 500 180 000 222 400 254 200 324 800 314 200 324 800 374 200 423 600M27 459 174 400 229 500 234 100 289 200 330 500 422 300 408 500 422 300 486 500 550 800M30 561 213 200 280 500 286 100 353 400 403 900 516 100 499 300 516 100 594 700 673 200M33 694 263 700 347 000 353 900 437 200 499 700 638 500 617 700 638 500 735 600 832 800M36 817 310 500 408 500 416 700 514 700 588 200 751 600 727 100 751 600 866 000 980 400M39 976 370 900 488 000 497 800 614 900 702 700 897 900 868 600 897 900 1 035 000 1 171 000

1) If the description of the thread does not include thread pitch then the reference is to coarse threads (see ISO 261 and ISO 262).

Designation system and stress under proof load for nuts with height 0,5 d, but < 0,8 d


Test loads for nuts




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Nuts with test loads above 350 000 N (values highlighted in blue) can be excluded from a test load trial. The buyer and the manufacturermust agree minimum hardnesses for these particular nuts.

Thread1) Nominal stressarea of thematerial AS[mm2]

Test load (AS x Sp), [ N ]Property class (code number)

4 5 6 8 10 12M3 5,03 2 500 3 000 4 000 5 000 6 000M3,5 6,78 3 400 4 050 5 400 6 800 8 150M4 8,78 4 400 5 250 7 000 8 750 10 500M5 14,2 7 100 8 500 11 400 14 200 17 000M6 20,1 10 000 12 000 16 000 20 000 24 000M7 28,9 14 500 17 300 23 000 29 000 34 700M8 36,6 18 300 22 000 29 000 36 500 43 000M10 58,0 29 000 35 000 46 000 58 000 69 500M12 84,3 42 100 50 500 67 000 84 000 100 000M14 115 57 500 69 000 92 000 115 000 138 000M16 157 78 500 94 000 126 000 157 000 188 000M18 192 76 800 96 000 115 000 154 000 192 000 230 000M20 245 98 000 122 000 147 000 196 000 245 000 294 000M22 303 121 000 151 000 182 000 242 000 303 000 364 000M24 353 141 000 176 000 212 000 282 000 353 000 423 000M27 459 184 000 230 000 276 000 367 000 459 000 550 000M30 561 224 000 280 000 336 000 448 000 561 000 673 000M33 694 277 000 347 000 416 000 555 000 694 000 833 000M36 817 327 000 408 000 490 000 653 000 817 000 980 000M39 976 390 000 488 000 585 000 780 000 976 000 1 170 000

1) If the designation of the thread does not indicate thread pitch then the reference is to coarse threads (see DIN 13).

Property class Chemical composition in terms of % by weight(test analysis)C Mn P Smax. min. max. max.

41), 51), 61) 0,50 0,060 0,1508, 9 041) 0,58 0,25 0,060 0,150102) 052) 0,58 0,30 0,048 0,058122) 0,58 0,45 0,048 0,058

1) Nuts of these strength classes may be made from free cutting steel, unlessother arrangements have been agreed upon between the buyer and thesupplier. When using free cutting steel, the following maximum proportionsof sulphur, phosphorus and lead are permitted:sulfur 0,34 % phosphorus 0,11 % lead 0,35 %

2) For these strength classes it may be necessary to add alloys in order toachieve the mechanical properties of the nuts.

Note Nuts of property classes 05, 8 (style 1 above M16 or style 1fine thread), 10 and 12 must be quenched and tempered.

Test loads for nuts 0,8 d

according to DIN 267, part 4

Chemical compositions of nuts






, 2 0 1 2

. 0 6

Mechanical properties Property class1)

14 H 22 H 33 H 45 HVickers hardness HV min. 140 220 330 450

max. 290 300 440 560Brinell hardness HB,F = 30D2

min. 133 209 314 428max. 276 285 418 532

Rockwell hardness HRB min. 75 95 max. 105

Rockwell hardness HRC min. 33 45max. 30 44 53

Surface hardness HV 0,3 max. 320 450 5801) Property class 14 H, 22 H and 33 H are not for hexagon socket set screws

The mechanical properties apply to grub screws and similar,which arenot subject to tension and which have threads ofdiameter from 1,6 to 39 mm, made from unalloyed or alloyedsteel.For further details of the mechanical properties of set screwsplease refer to ISO 898, part 5.

Mechanical properties


Property class Material Heat treatment Chemical compositionin % by weight (random analysis)C P S

min. max. max. max.14 H High-carbon steel1) 2) 0,50 0,11 0,1522 H High-carbon steel3) quenched and tempered 0,50 0,05 0,0533 H High-carbon steel3) quenched and tempered 0,50 0,05 0,0545 H Alloy steel3) 4) 5) 6) quenched and tempered 0,19 0,50 0,05 0,05

1) Free-cutting steel may be used, with lead content 0,35 % maximum, phosphorus content 0,11 % maximum and sulphur content 0,34 % maximum.2) Case hardening is allowed in the case of square-head set screws.3) Steel with lead content 0,35 % maximum may be used.4) The alloying steel must contain an alloying element or several alloying elements like chromium, nickel, molybdenum, vanadium or bor.5) For thread pins with property class 45H other steels may be used if the conditions of the torque test is conform to ISO 898, part 5. Boron alloyed steels shall

content boron between 0,0008 and 0,005. Hard steel is permitted with min. 0,45 % C if alloying elements contains at least 50 % according to ISO 8981, part 1.6) To M16 boron alloyed carbon steel contents min. 0,35 % C.

Materials, heat treatment and chemical composition



Set screws Property classes 14 H to 45 H



, 2 0 1 2

. 0 6

Marking symbols Property class4.6 4.8 5.6 5.8 6.8 8.8 9.8 10.9 12.9 12.9

Marking symbols for fasteners with

full loadability1)

4.6 4.8 5.6 5.8 6.8 8.8 9.8 10.9 12.9 12.9

Marking symbols for fasteners withreduced loadability 1)

04.6 04.8 05.6 05.8 06.8 08.8 09.8 010.9 012.9 012.9

1) The dot in the marking symbol may be omitted.

Identification with the manufacturers mark and the property classis mandatory for hexagon screws 4.6 to 12.9 and socket headcap screws 8.8 to 12.9 with thread diameter d 5 mm, where theshape of the screw always allows it. (Marking of bolts and screwsare preferably on the head).

ABCD 8.8

8.8

ABCD

Examples of marking on hexagonscrews and bolts.

ABCD 12.9

12.9

ABCD

8.8

XYZ

Examples of marking on hexagon andhexalobular socket head cap screws.

Marking of fasteners


The revised standard as of April 2009 has been for the applicationfor bolts, screws and studs with specified property classes coarse thread and fine pitch thread.

Fasteners according to a product standard with reduced loadabil-ity need to be marked with property class preceded with the digit"0". The objective of the revised head marking is an indicativeinstruction for the assembly process. The user can further look upfor additional notes in the Bossard catalogue. The revised headmarking is a defined identification in accordance to the revisedstandard.

Judgment of the change for the user:

Fasteners that are manufactured according to the oldstandard have no functional differences compared to therevised standard.

Fasteners according to the mentioned specification arealways subjected to reduced loadability due to the headgeometry according to ISO 898-1 this means thattightening torques has to be taken into account.

Marking and designation of fasteners with reduced loadability



Screws, bolts, nuts



, 2 0 1 2

. 0 6

Marking of nuts


Identification with the manufacturer is mark and property classis mandatory for hexagon nuts with thread diameter d 5 mm.The hexagon nuts must be marked with an indentation on thebearing surface or on the side or by embossing on the chamfer.Embossed markings must not protrude beyond the bearingsurface of the nut.

AB AB

Example of marking with the codesymbol (clock-face system)

8 AB

AB

8

Example of marking with the propertyclass designation


Screws, bolts, nuts

Marking is obligatory for property classes of or higher than 5.6and is preferably to be made on the threaded part by an indenta-tion. For adjustment bolts with locking, the marking must be onthe side of the nut.Marking is required for bolts of nominal diameter of or greaterthan 5 mm.

The symbols shown in the table on the right are also authorisedas a method of identification.

8 . 8

X Y Z

8.8

Marking of studbolts


Property class 5.6 8.8 9.8 10.9 12.9

Marking symbol



, 2 0 1 2

. 0 6

1) Quenched and tempered material

Mating bolts Nuts

Property class Diameter range

Property class Diameter range Type 1 Type 2 Type 0,5 d3.6 to 12.9reduced loadability

M39 04 < M3905 < M391)

3.6, 4.6, 4.8 > M16 4 > M16 3.6, 4.6, 4.8 M16 5 M16 5.6, 5.8 M39 > M16 M396.8 M39 6 M39 08.8reduced loadability

M39 |8| M16 > M16 M39 > M16 M391)

8.8 M39 8 M16 > M16 M39

> M16 M391)9.8 M16 9 M16 10.9 M39 10 M391) 12.9 M39 12 M161) M391)

Assignment of possible property classes of screws and nuts

RemarkIn general, nuts of a higher property class are preferable tonuts of a lower property class. This is advisable for a bolt / nutassembly stressed higher than the yield stress or the stressunder proof load.

Pairing screws and nuts 0,8 d


|8|

|8|

Groove

Marking of nuts


Property class

Characteristic 4 5 6 8 10 12Identification mark |4| |5| |6| |8| |10| |12|

Hexagon nuts with nominal thread diameter d 5 mm must bemarked with the property class on the bearing surface or on theside. Embossed markings must not protrude beyond the bearingsurface of the nut.

For hexagon nuts with nominal thread diameter d 5 mm acc. toDIN 934 and DIN 935 made from free-cutting steel, the markingmust also include a groove on one chamfer of the nut (up toproperty class 6).


Screws, bolts, nuts



, 2 0 1 2

. 0 6

Mechanical properties min. 0,2 % yield strength values at increased temperatures

according to DIN EN 10269 (old DIN 17240)Material abbreviation Diameter

rangeTensilestrength

Elongationat facture

notch barimpact value

Minimum value for the 0,2 % limitRp0,2 at [N/mm2]at a temperature [C] of

Material d Rm Amin KVminName number [mm] [N/mm2] [%] [J] 20 100 200 300 400 500 600hardened and tempered steelsC35E 1.1181 d 60 500 to 650 22 55 300 270 229 192 17335B2 1.5511 d 60 500 to 650 22 55 300 270 229 192 17325CrMo4 1.7218 d 100 600 to 750 18 60 440 428 412 363 304 23542CrMo4 1.7225 d 60 860 to 1060 14 50 730 702 640 562 475 37540CrMoV4-7 1.7711 d 100 850 to 1000 14 30 700 670 631 593 554 470 293X22CrMoV12-1 1.4923 d 160 800 to 950 14 27 600 560 530 480 420 335X19CrMoNbVN11-1 1.4913 d 160 900 to 105012 20 750 701 651 627 577 495 305work-hardened austenitic steelsX5CrNi18-10 1.4301 d 35 700 to 850 20 80 350 155 127 110 98 92X5CrNiMo17-12-2 1.4401 d 35 700 to 850 20 80 350 175 145 127 115 110X5NiCrTi26-5 1.4980 d 160 900 to 1150 15 50 600 580 560 540 520 490 430

Material abbreviation Density Static modulus of elasticity E in [kN/mm2]at a temperature [C]

Material Name number [kg/dm3] 20 100 200 300 400 500 600hardened and tempered steels

C35E 1.1181 7,85 211 204 196 186 177 164 12740CrMoV4-7 1.7711X19CrMoNbVN11-1 1.4913 7,7 216 209 200 190 179 167 127X22 CrMoV12-1 1.4923work-hardened austenitic steelsX5CrNi18-10 1.4301 7,9 200 194 186 179 172 165 X5CrNiMo17-12-2 1.4401 8,0X5NiCrTi26-15 1.4980 8,0 2111) 2061) 2001) 1921) 1831) 1731) 1621)

Typical values for the coe cient of thermal expansion, thermal conductivity and heat capacity

excerpt from DIN EN 10269 (old DIN 17240)

1) Dynamic modulus of elasticity

Material abbreviation Coefficient of thermal expansion in 10-6 / Kbetween 20 C and

Thermal conductivityat 20 C

Specific thermalconductivity at 20 C

MaterialName number 100 C 200 C 300 C 400 C 500 C 600 C [w/(mK)] [J/(kgK)]hardened and tempered steelsC35E 1.1181 11,1 12,1 12,9 13,5 13,9 14,1 42 46040CrMoV4-7 1.7711 33work-hardened austenitic steelsX5CrNi18-10 1.4301 16,0 16,5 17,0 17,5 18,0 n. a. 15 500X5CrNiMo17-12-2 1.4401X5NiCrTi26-15 1.4980 17,0 17,5 17,7 18,0 18,2 n. a. n. a. n. a.

n. a. = no data available

Typical values for the density and static modulus of elasticity

according to DIN EN 10269 (old DIN 17240)


Screws and nuts for high and low temperatures



, 2 0 1 2

. 0 6

Material abbreviation

Utilisation temperature limitsName Material number MarkingC35E (N)1) 1.1181 Y +350 CC35E (QT) 1.1181 YK +350 C2)35B2 1.5511 YB +350 C2)24CrMo5 1.7258 G +400 C25CrMo4 1.7218 KG +400 C42CrMo4 1.7225 GC +500 C21CrMoV5-7 1.7709 GA +540 C40CrMoV4-6 1.7711 GB +520 CX22CrMoV12-1 1.4923 V3), VH4) +580 CX19CrMoNbVN11-1 1.4913 VW +580 CX7CrNiMoBNb16-16 1.4986 S +650 CX6NiCrTiMoVB25-15-2 1.4980 SD +650 CNiCr20TiAl 2.4952 SB +700 C

1) Applies only to nuts2) For nuts the usual upper bound of the temperature in service may be around 50 C higher.3) Symbol V for material with a 0,2 % proof strength Rp0,2 600 N/mm24) Symbol VH for material with a 0,2 % proof strength Rp0,2 700 N/mm2

Material abbreviation

Utilisation temperature limitsName Material number Marking Screws25CrMo4 1.7218 KG 60CX12Ni5 1.5680 KB 120 CX5CrNi18-10 1.4301 A21) 200 CX4CrNi18-12 1.4303 A21) 200 CX2CrNi18-9 1.4307 A2L1) 200 CX6CrNiMoTi-17-12-2 1.4571 A51) with head2)

without head2)60 C200 C

X2CrNi17-12-2 1.4404 A4L1) with head2) 60 Cwithout head2) 200 C

1) The property class must be added to this marking of austenitic steel grades,e.g. A270 Application temperatures down to 200 C for screw property class 70and 80, nut property class 80. Lower strengths down to 60 C.

2) As a result of the molybdenum content when below the temperature shown these can no longer be expected to have a homogenous austenitic micro-structure.

Material Screw Material NutC35E (QT), 35B2 C35E (N), C35E (QT), 35B225CrMo4, 24CrMo5 C35E (QT), 35B2, 25CrMo421CrMoV5-7 25CrMo4, 21CrMoV5-740CrMoV47, 42CrMo4 21CrMoV5-7, 42CrMo4X22CrMoV12-1 X22CrMoV12-1X19CrMoNbVN11-1 X22CrMoV12-1

X7CrNiMoBNb16-16 X7CrNiMoBNb16-16X6NiCrTiMoVB25-15-2 X6NiCrTiMoVB25-15-2NiCr20TiAl NiCr20TiAl

NoteAt the lower limits of the operation temperature indicated in thetable, the impact work of notched bar (KV) of the material mustbe at least 40 Joules.

Table of materials for temperature over +300 C




Table of materials for low temperatures from 200 C to 10 C


Pairing materials for screws and nuts




, 2 0 1 2

. 0 6

Temperature [C]

70

60

50

40

30

20

10

0

[%]

-200 -150 -100 -50 0 +20

Necking at rupture KElongation at rupture AImpact strength specimen DVM

DVM [J]

200

100

0

26 CrMo 4X 12 CRNi 18 9

12 Ni 19X 12 CrNi 18 9X 10 CrNiTi 18 10X 10 CrMoTo 18 10

12 Ni 1926 CrMo4

X 12 CrNi 18 9X 10 CrNiTi 18 1012 Ni 1926 CrMo4

{{

[N/mm 2]

1300

1200

1100

1000

900

800

700600

500

400

300

200

100

0

Temperature [C]

-200 -150 -100 -50 0 +20

26 CrMo 412 Ni 19

X 12 CrNi 18 9X 10 CrNiTi 18 1026 CrMo 4 (to -120 C)12 Ni 19

X 12 CrNi 18 9X 10 CrNiTi 18 10

Tensile strength R mYield strength R eL or R p 0,2

Ductility of steels at low temperatures

according to manufacturers speci cations

Yield strength and tensile strength of steels at low temperatures

according to manufacturers speci cations





, 2 0 1 2

. 0 6

Materials Elastic elongation [mm] prestressed up to approx. 70 % of yield stress at room temperatureL [mm] YK G GA GB V VW S SBE [103 N/mm2] 211 211 211 211 216 216 196 21660 0,056 0,088 0,109 0,139 0,116 0,152 0,107 0,11670 0,065 0,102 0,127 0,162 0,136 0,177 0,125 0,13680 0,074 0,117 0,146 0,186 0,155 0,202 0,143 0,15590 0,084 0,131 0,164 0,209 0,175 0,228 0,161 0,175100 0,093 0,146 0,182 0,232 0,194 0,253 0,179 0,194110 0,102 0,161 0,200 0,255 0,213 0,278 0,197 0,213120 0,112 0,175 0,218 0,278 0,233 0,304 0,215 0,233130 0,121 0,190 0,237 0,302 0,252 0,329 0,233 0,252140 0,130 0,204 0,255 0,325 0,272 0,354 0,251 0,272150 0,140 0,291 0,273 0,348 0,291 0,280 0,269 0,291160 0,149 0,234 0,291 0,371 0,310 0,405 0,286 0,310170 0,158 0,248 0,309 0,394 0,330 0,430 0,304 0,330180 0,167 0,263 0,328 0,418 0,349 0,455 0,322 0,349190 0,177 0,277 0,346 0,441 0,369 0,481 0,340 0,690200 0,186 0,292 0,364 0,464 0,388 0,506 0,358 0,388210 0,195 0,307 0,382 0,487 0,407 0,531 0,376 0,407220 0,205 0,321 0,400 0,510 0,427 0,557 0,394 0,427230 0,214 0,336 0,419 0,534 0,446 0,582 0,412 0,446240 0,223 0,350 0,437 0,557 0,466 0,607 0,430 0,466250 0,233 0,365 0,455 0,580 0,485 0,633 0,448 0,485260 0,242 0,380 0,473 0,603 0,504 0,658 0,465 0,504270 0,251 0,394 0,491 0,626 0,524 0,683 0,483 0,524280 0,260 0,409 0,510 0,650 0,543 0,708 0,501 0,543290 0,270 0,423 0,528 0,673 0,563 0,734 0,519 0,563300 0,279 0,438 0,546 0,696 0,582 0,759 0,537 0,582

Calculation

= [mm]

[mm] = elastic elongation under preload FV

FV [N] = preloadE [N/mm2] = elasticity moduleA [mm2] = cross section area of reduced shankL [mm] = reduced shank length

where:

0,7 = 70 % Rp 0,2

Overview of material Page T.017

L

FV

A

FV

Length of reduced shank

Example

X8CrNiMoBNb16-16 = [S]Rp 0,2 = 500 N/mm2length of reduced shank L = 220 mm

Elastic elongation

= 0,7 500 = 0,394 mm

see table:column S for L = 220 mm

220196000

FVA

FV LE A

Elastic elongation of bolts with reduced shanks

according to DIN 2510





, 2 0 1 2

. 0 6

Steel group

F1(C3 3))

Identification of steelgrades

Screws, nuts type 1

FerriticMartensiticAustenitic

C4A42)A31)A22)A1 A51)

Jam nuts

Property classes

Studs, setscrews

Tapping screws

C4C1

soft coldworked

highstrength

soft hardenedand

tempered

soft hardenedand

tempered

hardenedand

tempered

soft coldworked

1) Stabilized against intergranular corrosion through addition of titanum, possibly niobium, tantalum.2) Low carbon austenitic stainless steels with carbon content not exceeding 0,03 % may additionally be marked with an "L", e.g. A4L-80.3) For tapping screws steel grade C3 is used.

Descriptions using a letter/ gure combination mean the following:

Abbreviation of composition group:A = austenitic chromium-nickel steel

Abbreviation of chemical composition:1 = free-cutting steel with sulphur additive2 = cold-heading steel alloyed with chromium and nickel3 = cold-heading steel alloyed with chromium and nickel stabilised with Ti, Nb, Ta4 = cold-heading steel alloyed with chromium, nickel and molybdenum5 = cold-heading steel alloyed with chromium, nickel and molybdenum

stabilized with Ti, Nb, Ta

Abbreviation of property class:50 = 1/10 of tensile strength (min. 500 N/mm2)70 = 1/10 of tensile strength (min. 700 N/mm2)80 = 1/10 of tensile strength (min. 800 N/mm2)

A2 70

Thin nuts:025 = proof stress min. 250 N/mm2035 = proof stress min. 350 N/mm2040 = proof stress min. 400 N/mm2

The designation of the steel grade ( rst block) consists of one of the letters: A for austenitic steel C for martensitic steel F for ferritic steel

Example: A2-70 indicates: austenitic steel, cold worked, min. 700 N/mm2 tensile strength C4-70 indicates: martensitic steel, hardened and tempered, min. 700 N/mm2 tensile

strength The designation of the property class consists of two digits representing 1/10 of the

tensile strength of the fasteners respectively 1/10 of the proof load of the nuts.

If fastener elements are classi ed over the hardness, the hardness class is given according to Vickers by 2 digits standing for 1/10 ofthe minimum hardness value. The letter H refers to the hardness.

Designation example of a minimum hardness 250 HV:A4 25 H, austenitic steel, cold strengthened

ISO-designated steel groups

according to ISO 3506


Stainless steel fasteners



, 2 0 1 2

. 0 6

More than 97 % of all fasteners made from stainless steels areproduced from this steel composition group. They are character-ised by impressive corrosion resistance and excellent mechanicalproperties.

Steelgroup

Chemical composition in %(maximum values, unless otherwise indicated)

Notes

C Si Mn P S Cr Mo Ni CuA1 0,12 1,0 6,5 0,200 0,150,35 1619 0,7 510 1,752,25 2) 3) 4)

A2 0,10 1,0 2,0 0,050 0,03 1520 819 4 5) 6)

A3 0,08 1,0 2,0 0,045 0,03 1719 912 1 1) 7)

A4 0,08 1,0 2,0 0,045 0,03 1618,5 23 1015 4 6) 8)

A5 0,08 1,0 2,0 0,045 0,03 1618,5 23 10,514 1 1) 7) 8)

1) Stabilized against intergranular corrosion through addition of titanium, possibly niobium, tantalum.2) Sulfur may be replaced by selenum.3) If the nickel content is below 8 %, the min. manganese content shall be 5 %.4) There is no min. limit to the copper content, provided that the nickel content is greater than 8 %.5) If the chromium content is below 17 %, the min. nickel content should be 12 %.6) For austenitic stainless steels having a max. carbon content of 0,03 %, nitrogen may be present to a max. of 0,22 %.7) This shall contain titanium 5 x C up to 0,8 % max. for stabilization and be marked appropriately as speci ed in this table, or shall

contain niobium (columbium) and/or tantalum 10 x C up to 1 % maximum for stabilization and be marked approprately as speci ed inthis table.

8) At the discretion of the manufacturer, the carbon content may be higher where required in order to obtain the speci ed mechanicalproperties at larger diameters, but shall not exceed 0,12 % for austenitic steels.

Materialnumber

Chemical composition, % by massC Si Mn P S Cr Mo Ni Other

max. max. max. max.Martensitic steels1.4006 0,08 to 0,15 1,0 1,5 0,04 0,030 11,0 to 13,5 max. 0,751.4034 0,43 to 0,50 1,0 1,0 0,04 0,030 12,5 to 14,51.4105 max. 0,08 1,0 1,5 0,04 0,035 16,0 to 18,0 0,20 to 0,601.4110 0,48 to 0,60 1,0 1,0 0,04 0,015 13,0 to 15,0 0,50 to 0,80 V max. 0,151.4116 0,45 to 0,55 1,0 1,0 0,04 0,030 14,0 to 15,0 0,50 to 0,80 V 0,10 to 0,201.4122 0,33 to 0,45 1,0 1,5 0,04 0,030 15,5 to 17,5 0,80 to 1,30 max. 1,0Austenitic steels1.4301 max. 0,07 1,0 2,0 0,045 0,030 17,0 to 19,5 8,0 to 10,5 N max. 0,111.4305 max. 0,10 1,0 2,0 0,045 0,15 to 0,35 17,0 to 19,0 8,0 to 10,0 Cu max. 1,00 / N max. 0,11

1.4310 0,05 to 0,15 2,0 2,0 0,045 0,015 16,0 to 19,0 max. 0,80 6,0 to 9,5 N max. 0,111.4401 max. 0,07 1,0 2,0 0,045 0,030 16,5 to 18,5 2,00 to 2,50 10,0 to 13,01.4435 max. 0,03 1,0 2,0 0,045 0,030 17,0 to 19,0 2,50 to 3,00 12,5 to 15,0 N max. 0,111.44391) max. 0,03 1,0 2,0 0,045 0,025 16,5 to 18,5 4,00 to 5,00 12,5 to 14,5 N 0,12 to 0,221.45291) max. 0,02 0,5 1,0 0,030 0,010 19,0 to 21,0 6,00 to 7,00 24,0 to 26,0 N 0,15 to 0,25 / Cu 0,5 to 1,51.45391) max. 0,02 0,7 2,0 0,030 0,010 19,0 to 21,0 4,00 to 5,00 24,0 to 26,0 N max. 0,15 / Cu 1,2 to 2,01.44621) max. 0,03 1,0 2,0 0,035 0,015 21,0 to 23,0 2,50 to 3,50 4,5 to 6,5 N 0,10 to 0,221.4568 max. 0,09 0,7 1,0 0,040 0,015 16,0 to 18,0 6,5 to 7,8 Al 0,70 to 1,501.4571 max. 0,08 1,0 2,0 0,045 0,030 16,5 to 18,5 2,00 to 2,50 10,5 to 13,5 Ti 5xC 0,70

1) Austenitic stainless steels with particular resistance to chloride induced stress corrosion. The risk of failure of bolts, screws and studs by chloride induced stress corrosion (for example in indoor swimming pools) can be reduced by using thematerials marked in the table.

Austenitic stainless steels are divided into 5 main groups whosechemical compositions are as follows:

Chemical composition of austenitic stainless steels


Chemical composition of corrosion resistant stainless steels





, 2 0 1 2

. 0 6

Material designation A1 A2 A3 A4 A5Material number 1.4300 1.4301 1.4541 1.4401 1.4436

1.4305 1.4303 1.4590 1.4435 1.45711.4306 1.4550 1.4439 1.4580

Properties for machining Standard quality Highest resistance to corrosion rust-resistant to a certain

degree rust-resistant rust-resistant

corrosion-resistant to a certaindegree

acid-resistant highly acid-resistant

weldable to a certain degree weldable to a certain degree easily weldableA3, A5 as A2, A4 but stabilised against intergranular corrosion following welding,annealing or when used at high temperatures.

Further details on the chemical stability of rust-resistant andacid-resistant steels can be found on

Page T.023

Figure gives the approximate time for austenitic stainless steels,grade A2 (18/8 steels), with different carbon contents in the tempera -ture zone between 550 C and 925 C before risk of intergranularcorrosion occours.

Note With lower carbon contents, the resistance against intergranu-lar corrosion is improved.

Distinctive properties of stainless steels

Time-temperature diagram of intergranular corrosion in austenitic stainless steels

Time in minutes

T e m p e r a t u r e i n C




24/85



, 2 0 1 2

. 0 6

Screws

1) All values are calculated values and refer to the stressed cross-section of the thread.2) The elongation after fracture is to be determined for the whole screw and not for unscrewed test pieces.3) Strength requirements for diameters above M24 must be specially agreed on between the buyer and the manufacturer.

Nuts

m = nut heightd = nominal thread diameter

The commercial quality of steel grades A2 and A4 is propertyclass 70 (tensile strength 700 N/mm2), for thread diameters M5 toM24 and with lengths up to 8x thread diameter (8 x d).We keep a wide range available for you from stock.

Use of screws of property class 80 is only economically justifiableif the components are made from stainless steel (high strength).

Threads Minimum breaking torqueMB min[Nm]

Property class50 70 80

M1,6 0,15 0,2 0,24M2 0,3 0,4 0,48M2,5 0,6 0,9 0,96M3 1,1 1,6 1,8M4 2,7 3,8 4,3

M5 5,5 7,8 8,8M6 9,3 13 15M8 23 32 37M10 46 65 74M12 80 110 130M16 210 290 330

Mechanical properties for fasteners made from austenitic stainless steel


Reference values for 0,2 % R p0, 2 at higher temperatures as % of the values at roomtemperature

according to ISO 3506Steel grade1) 0,2 % Rp0,2

+100 C +200 C +300 C +400 CA2, A4 85 % 80 % 75 % 70 %

For applicability at low temperature see Seite T.017

1) applies for property classes 70 and 80

Steel group Steelgrade Property class Thread diameter range Tensile strengthRm min1)[N/mm2]

Stress at 0,2% perma-nent strain Rp 0,2 min1)[N/mm2]

Elongation after fractureAmin2)[mm]

Austenitic A1, A2 50 M39 500 210 0,6 dA3, A4 70 M24 3) 700 450 0,4 dA5 80 M243) 800 600 0,3 d

Steel group Steel grade Property class Thread diameter range Stress under proof load SP min [N/mm2]

Nuts Style 1 thin nuts d Nuts Style 1 thin nutsm 0,8 d 0,5 d m < 0,8 d [mm] m 0,8 d 0,5 d m < 0,8 dAustenitic A1, A2 50 025 39 500 250

A3, A4 70 035 24 3) 700 350A5 80 040 243) 800 400

Minimum breaking torque M B min for screws made from austenitic steel with threadsM1,6 to M16 (normal thread)






, 2 0 1 2

. 0 6

Marking of screws and nuts


RequirementScrews and nuts made from stainless austenitic steels must bemarked.

Caution Only those fasteners marked to standard will have the desiredproperties. Products not marked to standard will often onlycorrespond to property classes A2-50 or A4-50.

ScrewsHexagon and hexagon socket screws from nominal diameter M5must be marked. The marking must show the steel group, theproperty class and the manufacturers mark. Locking screws mustbe marked on the shaft or screw end.

StudboltsBolts from nominal diameter M6 must be marked on the shank orthe end of the thread with the steel group, the property class andthe manufacturers mark.

Hexagon screws

A 2

- 7 0

X Y Z

A2

XYZ

A2-70

manufacturers mark

Property classSteel group

XYZ

XYZ

A2

A2-70

-70

When the marking is made with grooves and the property class isnot indicated, property class 50 or 025 will apply.

It is possible that certain nuts would not fulfil the proof loadrequirements because of fine pitch thread or the geometry of thenut. These nuts may be marked with the steel grade, but shallnotbe marked with the property class.

>

s

A4 A2

Alternative groove marking(for steel grades A2 and A4 only)

Socket head cap screws

A A4-80

A

A4-80

NutsNuts from minimal diameter M5 must be marked with the steelgroup, the property class and the manufacturers mark.

Other markingsOther types of bolts and screws can be marked in the same way,where it is possible to do so and on the head portion only. Ad-ditional marking is allowed, provided it does not cause confusion.

Fasteners that do not fulfil the tensile or torsional requirementsbecause of the geometry may be marked with the steel grade, butshallnot be marked with the property class.

XYZ

A2

NoteMarkings analogous to ISO 898-1 using the supplementary0(e.g. A2-070) are intended to be included in the next revisionof ISO 3506-1.





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Properties of screws and nuts made from copper alloys selection based on information provided by the manufacturers

Properties of screws and nuts made from aluminium alloys selection based on information provided by the manufacturers

The values in the table are for: density = 2,8 kg/dm 3, coe cient of thermal expansion = 23,6 10 6 K1 , modulus of elasticity = 70 000 N/mm 2

Material designationEN AW-

MaterialnumberEN AW-

Old DINdesignation

Stage of preparation ofthe screws/nuts

Used for

Materialnumber

from EN28839

Rp 0,2[N/mm2]

Rm[N/mm2]

AS%

Al Mg5 5019 3.3555 AL 2 soft workhardened

< M14M14/M20

205200

310280

66

very good level of corrosion-resistancelow strength

Al Si1 Mg Mn 6082 3.2315 AL 3 hardenedT6

< M6M6/M20

260250

320310

710

very good level of corrosion-resistancemedium strength

Al Mg1 Si 0,8 Cu Mn 6013 hardenedT8

< M20 370 400 10 still a good level of corrosion-resistancehigh strength

Al Cu4 Mg Si 2017 A 3.1325 AL 4 hardenedT6 (F 42)

< M20 290 420 6 high strength mountings but lowest levelof corrosion resistance1)

Al Zn6 Cu Mg Zr 7050 3.4144 hardenedT73 (F 50)

< M30 400 500 6 high strength mountings but lowest levelof corrosion resistance

Al Zn5,5 Mg Cu 7075 3.4365 AL 6 hardenedT73 (F 51)

< M30 440 510 6

1) subject to stress corrosion cracking due to the high copper content


Fasteners of various materials

Materialdesignation

Materialnumber

Des.fromEN28839

State ofstructure

Density

Electricalconductivity

m

Coefficient ofthermalexpansiona 30/100 C

Mechanical propertiesat 20 C

Used for

F = Rm /10 [kg/dm3] [ mm2] [mm/mmK] Rp 0,2[N/mm2]

Rm[N/mm2]

AS min.%

E-Modul[N/mm2]

E-Cu 58OF-Cu

2.0065

2.0040Cu 1

F20 soft

F201)8,94

58,0

56,017,0 10-6

< 150

< 320

200/270

> 350

40

7110 000

parts with a highelectrical conductivity

CuZn 37(brass)

2.0321 10

2.0321 26Cu 2

F29 soft

F371)8,44 15,5 20,2 10-6

< 250

> 250

> 290

> 370

45

27110 000

normal fastenings

CuNi12 Zn24

(nickel silver)

2.0730 10

2.0730 30

F34 soft

F54 soft

8,67 4,4 18,0 10-6< 290

> 440

330/440

540/640

40

8

125 000very good corrosionresistant, silver colors

CuNi1,5SiCuNi3Si

2.0853 732.0857 73

Cu 5

hardenedhardened

8,88,8

> 18,0> 15,0

16,0 10-616,0 10-6

> 540> 780

> 540> 830

1210

140 000144 000

high-strength fastening,with very good electricalconductivity

CuBe2 2.124 75 hardened 8,3 ~10 16,7 10-6 1 050/ 1 400

1 200/ 1 500

2 125 000 high-strength fastening,corrosion resistant,good electricalconductivity

Non-ferrous metal

1) cold strain hardening



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Threadsnominal

Minimum breaking torque1)[Nm] for materialCU1 CU2 CU3 CU4 CU5 AL1 AL2 AL3 AL4 AL5 AL6

M1,6 0,06 0,10 0,10 0,11 0,14 0,06 0,07 0,08 0,1 0,11 0,12M2 0,12 0,21 0,21 0,23 0,28 0,13 0,15 0,16 0,2 0,22 0,25M2,5 0,24 0,45 0,45 0,5 0,6 0,27 0,3 0,3 0,43 0,47 0,5M3 0,4 0,8 0,8 0,9 1,1 0,5 0,6 0,6 0,8 0,8 0,9M3,5 0,7 1,3 1,3 1,4 1,7 0,8 0,9 0,9 1,2 1,3 1,5M4 1 1,9 1,9 2 2,5 1,1 1,3 1,4 1,8 1,9 2,2M5 2,1 3,8 3,8 4,1 5,1 2,4 2,7 2,8 3,7 4 4,5

Minimum breaking torque for screws up to M5 according to ISO 8839

1) the torque test is to be carried out in according to ISO 898-7

DesignationMaterial number Description and range of application, based on information provided by the manufacturer

Hastelloy B Highly corrosion resistant nickel-molybdenum alloy with excellent resistance against reducing media, in particular against allconcentrations of hydrochloric acid up to boiling point, moist chlorine water gas, sulphuric acid, phosphoric acid and alkalinesolutions. Adequate resistance to oxidising and reducing gases up to 800 C. Not recommended for strongly oxidising agents,iron and copper salts (see Hastelloy C).

Application: Components subject to strong chemical action, turbo-superchargers for jet engines etc.

B-2 2.4617B-3 2.4600

Hastelloy C Highly corrosion resistant nickel-chrome-molybdenum alloy with particularly high resistance against aggressive, oxidising andreducing media bleach solutions which contain free chorine, chlorites, hypochlorites, sulphuric acid and phosphoric acid,organic acids such as vinegar and formic acid, solutions of nitrates, sulphates and sulphites, chlorides and chlorates, chromatesand cyanogen compounds.

Application: Components subject to strong chemical action, in chemical processes and plants, exhaust cleaning systems,in the production of fibres and paper, waste disposal etc.

C-4 2.4610C-22 2.4602C-276 2.4819C-2000 2.4675

Hastelloy G Nickel-chrome-iron alloy with excellent resistance to corrosion in oxidising media.Application: In chemical process engineering, particularly suitable for the production of phosphoric acid and nitric acid,desulphurization plant etc.G-3 2.4619G-30 2.4603

Inconel Nickel-chrome alloy with good industrial properties at high temperatures up to and above 1000C and an excellent resistance tooxidation. Even resists corrosion from caustic materials.

Application: Heat treatment plant, nuclear energy technology, gas turbines, linings, ventilators and fans, chemical industry etc.

600 2.4816601 2.4851625 2.4856718 2.4668Monel Nickel-copper alloy with high strength and toughness over a wide range of temperatures.

Excellent resistance to corrosion by salt water and a large number of acids and alkaline solutions.Also suitable for parts used in presses and forges.

Application: Valves, pumps, mountings, mechanically stressed components exposed to seawater etc.

400 2.4360K-500 2.4375

Nimonic The nickel-based chrome materials are alloys with a particularly high fatigue strength and resistance to oxidisation.For high mechanical stresses at temperatures up to 1000 C. A wide variety of penetration hardening methods allow therelaxation and creep behaviour to be controlled.

Application: Rotating components subject to high temperatures, springs, fasteners, combustion chamber components, blades,washers, shafts etc.

75 2.495180A 2.495290 2.4969105 2.4634Titanium Reactive material with high strength in relation to its low density. Excellent resistance to corrosion in oxidising metals

which contain chloride.

Application: Components for weight-saving construction requiring high strength, subject to strong oxidising stresses, particularlyin the presence of chlorides. Chemical industry, seawater desalination, power station technology, medical technology etc.

Gr. 1 3.7025Gr. 2 3.7035Gr. 3 3.7055Gr. 4 3.7065Titanium Titanium alloy with a high specific strength.

Application: Components for the air and space industries, chemical processing technology, rotating components, fasteners,vehicle engineering etc.

Gr.5 3.7164/3.7165

Titanium Pure titanium alloyed with palladium. Increased resistance to corrosion, particularly against moist media which contain chloride.Grade 11 has increased properties of deformation.

Application : Chemical and petrochemical plant, housings etc.

Gr. 7 3.7235Gr. 11 3.7225

Special materials



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Thermoplastics

MaterialabbreviationDIN 7728

Density [g/cm3]DIN 53479

Tensile strength[N/mm2]DIN 53455

Fractureresistance %DIN 53455

Elasticity module[N/mm2]DIN 53457

Ball penetrationhardness, 10-secValue [N/mm2]DIN 53456

Impact strength[kJ/m2]DIN 53453

Ductility[kJ/m2]DIN 53453

PE-HD 0,94/0,96 18/35 100/1 000 700/1 400 40/65 without fracture without fracturePE-LD 0,914/0,928 8/23 300/1 000 200/500 13/20 without fracture without fracturePP 0,90/0,907 21/37 20/800 1 100/1 300 36/70 without fracture 3/17POM 1,41/1,42 62/70 25/70 2 800/3200 150/170 100 8PA 6 1,13 70/85 200/300 1 400 75 without fracture without fracturePA 66 1,14 77/84 150/300 2 000 100 without fracture 15/20

Reference values of physical characteristics according to manufacturers data


Specificresistance[ cm]DIN 53482

Surfaceresistance[]DIN 53482

Dielectric constant Dielectric loss factor Dielectric strength Surface leakage currentDIN 53483 DIN 53483 resistance DIN 5348050 Hz 106 Hz 50 Hz 106 Hz [kV/25 m]

ASTM D 149[kV/cm]DIN 53481

KA KB/KC

PE-HD > 1017 1014 2,35 2,34 2,4 104 2,0 104 > 700 3 c > 600PE-LD > 1017 1014 2,29 2,28 1,5 104 0,8 104 > 700 3 b > 600PP > 1017 1013 2,27 2,25 < 4 104 < 5 104 800 500/650 3 c > 600POM > 1015 1013 3,7 3,7 0,005 0,005 700 380/500 3 b > 600PA 6 1012 1010 3,8 3,4 0,01 0,03 350 400 3 b > 600PA 66 1012 1010 8,0 4,0 0,14 0,08 400 600 3 b > 600


Operating temperature C Dimensional stability C Linear coefficientof expansion

Thermalconductivity

Specific heatVSP (Vicat5 kg)DIN 53460

ASTM D 6481,86/0,45

max. short therm max. permanent min. permanent [N/mm2] K1 10-6 [W/mK] [kJ/kg K]PE-HD 90/120 70/80 50 60/70 50 200 0,38/0,51 2,1/2,7PE-LD 80/90 60/75 50 35 250 0,32/0,40 2,1/2,5PP 140 100 0/30 85/100 45/120 150 0,17/0,22 2,0POM 110/140 90/110 60 160/173 110/170 90/110 0,25/0,30 1,46PA 6 140/180 80/100 30 180 80/190 80 0,29 1,7PA 66 170/200 80/120 30 200 105/200 80 0,23 1,7

Abbreviation Signi cancePE-HD High density polyethylenePE-LD Low density polyethylenePP PolypropylenePOM Polymethylene, PolyacetalePA 6 Polyamide 6PA 66 Polyamide 6.6

Mechanical properties

Electrical properties

Thermal properties

Instructions for screws made of thermoplastic materials

Mechanical and physical properties, especially tensilestrength and preload as well as colour, tolerances ofthreaded section and head geometry are subject to climaticconditions. Consult DIN 34810 and ISO 4759-1 for tolerancevalues, advice and assembly torques.

Preload can fall via stress relaxation. Instructions forconstruction and design are to be followed on the basis ofVDI 2544.




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Elastomere

Material shortmarkISO 1629

CR FPM NBR EPDM TPE

Material designation Chloropren-Caoutchouc

Flourine-Caoutchouc

Acrylonitrile-Buta-diene-Caoutchouc

Ethylene-Propylene-Diene-Caoutchouc

ThermoplasticElastomer

Combustibility UL 94 - V2 UL 94 - V2 UL 94 HB UL 94 HB UL 94 HBTemperaturerange1)

min. 30 C 20 C 30 C 40 C 30 Cmax. continually +100 C +200 C +120 C +130 C +80 C

intermittent +120 C +280 C +150 C +170 C +120 C

Combustibility

Chemical resistance 2)


CR FPM NBR EPDM TPE

Material designation Chloropren-Caoutchouc Flourine-Caoutchouc Acrylonitrile-Butadiene-Caoutchouc Ethylene-Propylene-Diene-Caoutchouc ThermoplasticElastomerAlcohol A A A A ABenzine C A A C BDiesel oil C A A C BMineral oil B A A B BAnimal and vegetariangreases

B A A B A

Weak alkaline solution A B B A AStrong alkaline solution B C C A BWeak acids B A B A AStrong acids C A C A AWater C A C A AOzone C A C A A

2) The following details should be regarded as guidelines only. Any more definite information can only be given with reference to the particular application inhand. For example, a precision part may fail simply on account of a slight change in volume, or aggressive media may in fact be usable as cleansing agent ifonly briefly in contact with the material in question.

A Very good, chemical resistance. Constant action of medium causes no damage to plastic within a period of 30 days. The plastic may remain resistantover a period of several years.

B Good to limited chemical resistance. Constant action of medium may cause slight damage within a period of 7 to 30 days, this damage some timesbeing reversible (swelling, softening, reduction in mechanical strength, discolouration).

C Low chemical resistance. Unsuitable for subjection to constant action of medium. Damage may occur immediately (reduction in mechanical strength,deformation, discolouration, cracks, dissolution).

1) Minus values in temperature range apply only to parts in idle state without impact stress.


CR FPM NBR EPDM TPE

Material designation Chloropren-Caoutchouc

Flourine-Caoutchouc

Acrylonitrile-Butadiene-Caoutchouc

Ethylene-Propylene-Diene-Caoutchouc

ThermoplasticElastomer

halogen free yes yes yesphosphate free yes yes yes yes yessilicone free yes yes yes yes yes

Chemical ingredients





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Corrosion protection

Galvanic process

Fasteners with electroplated coatingsaccording to ISO 4042

Galvanizing Passivation. Galvanizing followed by passivationof fasteners is a procedure which has proven itself in terms ofboth corrosion resistance and appearance. We can offer you anextensive assortment from our range in stock.

Passivation (chromalize) takes place immediately after thegalvanizing, and is made by briefly dipping the part in solutions ofchromic acid. The chromate treatment increases the corrosionprotection and prevents tarnishing and discoloration of the zinccoating. The protective effect of the layer of chromate differs withthe different types of procedure (see the table!).

New developments in processes involving chromium(VI)-free coatings offering the same or similar protective effectspurred onwards by environmental regulations due to EU Direc-tives 2000/53/EC (ELV) und 2002/95/EC (RoHS). Until nownormal practice has been to use galvanic zinc coatings (ISO4042) with chromate treatment based on chromium (VI) for thecorrosion protection of fasteners. The new surface treatmentsbased on chromium (VI) free systems usually require a morecomplex process control and where necessary additional coverlayers, since the self-healing effect is missing. Long-term ex-perience gained under working conditions is largely not availableand such experience is also influenced by specific conditionssuch as handling, transport and feeder devices. Consequently itis recommended that a review be made through the adjustmentfor the different operating conditions met in practice.

Types of procedure used for the passivation of electroplated zinc coatingsProtective e ect of zinc coatings with passivation under conditions of salt spray testing to ISO 9227 (DIN 50021 SS).

Types of process Designation of thepassivation

Chromate coating own color

Nominal thickness onthe coating

First appearance of

White rust, hours Red rust, hoursm h h

Colorless passivation A transparent 3 2 125 6 248 6 48

Blue passivation B transparent, 3 6 12with a tinge of blue 5 12 36(standard) 8 24 72

Yellow chromated C yellowish lustre to

yellow-brown iridescent

3 24 24

5 48 728 72 120

Olive chromated D olive-green toolive-brown (rare)

3 24 245 72 968 96 144

Black chromated1) BK blackish brown toblack (decorative)

3 5 12 8 24 72

1) On edges, the edges of the Phillips recess etc. use of the drum process means that you can practically always expect the black chromate coating to berubbed off here and the underlying light-colored zinc coating to become locally visible.

Reduction of the risk of hydrogen embrittlement (ISO 4042)

There is a risk of failure due to hydrogen embrittlement in galvani-cally finished fasteners which are under tensile stress and whichare made from steels with tensile strengths of Rm 1000 N/mm2,corresponding to 320 HV.

Heat treatment (tempering) of the parts, e.g. after the acid pick-ling or metal coating process, will reduce the risk of breakage.However it cannot be guaranteed that the risk of hydrogenembrittlement will be removed completely. If the risk of hydrogenembrittlement must be reduced, then other coating proceduresshould be considered.

Alternative methods of corrosion protection or coating shouldtherefore be selected for parts which are important to safety,alternatives such as anorganic zinc coating, mechanicalgalvanization or a switch to rust- and acid-resistant steels.

Where the method of fabrication allows, fasteners in classes 10.9 ( HV320) are provided with an anorganic zinc coating orare mechanically galvanized.The user of the fasteners knows the purposes and requirementsfor which the fasteners are to be used and he must specify theappropriate type of surface treatment!



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Threadpitch

P

Nominalthread

diameter1)

d1

Internal thread External threadTolerance position G Tolerance position g Tolerance position f Tolerance position e

Funda-mentalde-viation

Coatingthickness

Funda-mentalde-viation

Nom. coating thickness Grund-abmass

Nom. coating thickness Grund-abmass

Nom. coating thickness

max.2) max.3) max.2) max.3) max.2) max.3)

Overalllength

Nom. length l Overalllength

Nom. length l Overalllength

Nom. length l

5d 10d 15d 5d 10d 15d 5d 10d 15d

[mm] [mm] [m] max. [m] [m] [m] [m] [m] [m] [m] [m] [m] [m] [m] [m] [m] [m] [m] [0,2 +17 3 17 3 3 3 3 0,25 1; 1,2 +18 3 18 3 3 3 3 0,3 1,4 +18 3 18 3 3 3 3 0,35 1,6 (1,8) +19 3 19 3 3 3 3 34 8 8 5 5 0,4 2 +19 3 19 3 3 3 3 34 8 8 5 5 0,45 2,5 (2,2) +20 5 20 5 5 3 3 35 8 8 5 5 0,5 3 +20 5 20 5 5 3 3 36 8 8 5 5 50 12 12 10 80,6 3,5 +21 5 21 5 5 3 3 36 8 8 5 5 53 12 12 10 80,7 4 +22 5 22 5 5 3 3 38 8 8 5 5 56 12 12 10 80,75 4,5 +22 5 22 5 5 3 3 38 8 8 5 5 56 12 12 10 80,8 5 +24 5 24 5 5 3 3 38 8 8 5 5 60 15 15 12 101 6 (7) +26 5 26 5 5 3 3 40 10 10 8 5 60 15 15 12 101,25 8 +28 5 28 5 5 5 3 42 10 10 8 5 63 15 15 12 101,5 10 +32 8 32 8 8 5 5 45 10 10 8 5 67 15 15 12 101,75 12 +34 8 34 8 8 5 5 48 12 12 8 8 71 15 15 12 102 16 (14) +38 8 38 8 8 5 5 52 12 12 10 8 71 15 15 12 102,5 20 (18; 22) +42 10 42 10 10 8 5 58 12 12 10 8 80 20 20 15 123 24 (27) +48 12 48 12 12 8 8 63 15 15 12 10 85 20 20 15 123,5 30 (33) +53 12 53 12 12 10 8 70 15 15 12 10 90 20 20 15 154 36 (39) +60 15 60 15 15 12 10 75 15 15 15 12 95 20 20 15 154,5 42 (45) +63 15 63 15 15 12 10 80 20 20 15 12 100 25 25 20 155 48 (52) +71 15 71 15 15 12 10 85 20 20 15 12 106 25 25 20 155,5 56 (60) +75 15 75 15 15 15 12 90 20 20 15 15 112 25 25 20 156 64 +80 20 80 20 20 15 12 95 20 20 15 15 118 25 25 20 15

Coating thicknesses for parts with external thread


1) Information for coarse pitch threads is given for information. The determining characteristic is the thread pitch.2) Maximum values of nominal coating thickness if local thickness measurement is agreed.3) Maximum values of nominal coating thickness if batch average thickness measurement is agreed.

If no particular plating thickness is speci ed, the minimum platingthickness is applied. This is also considered the standard platingthickness.

In the case of parts with very long thread or small dimensions ( M4),an irregular coating thickness may occur due to the processing. Thiscan cause assembly problems.Possible solution: Use of a chemical nickel plating or stainless steelscrews A2 or A4.

External threads are normally fabricated in tolerancezone 6g.

e and f tolerance are not common and require special methodsof screw manufacture. Minimum quantities, longer deliveryperiods and higher prices may make these economically unvi-able. An alternative is to use parts made from stainless steelA2. Internal threads have a thinner coating due to technicalreasons. How ever, this has no significance in practical usebecause when assembled these are protected by the coatingof the external thread of the screw.

Measuring points for coating thickness

Measuringpoint

Measuringpoint



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Further galvanic coating processes

Process Details

Nickel-plating Nickel-plating is decorative and provides effective corrosion protection. A hard coating, used in the electrical applianceand telecommunications industries. No coating abrasion occurs, especially with screws. Improves protection against

impregnation, see table below.Veralisation A special method of hard nickel-plating.Chromium-plating Usually following nickel-plating. Coating thickness about 0,4 m.

Chromium is decorative, enhances resistance to tarnishing and improves corrosion protection.Bright chromium-plated: high brightness finish.Matt chromium-plated: matt lustre (silk finish).Polished chromium-plated: grinding, brushing and polishing of the surface prior to coating electrolytically (done by hand).Drum chromium plating not possible.

Brass-plating Brass plating is mainly applied for decorative purposes. In addition, steel components are brass-plated in order toimprove the adhesion of rubber to steel.

Copper-plating Used when necessary as intermediate coating prior to nickel-plating-chromium-plating and silver-plating.Used for decorative purposes.

Silver-plating Silver-plating is employed for decorative and technical applications.Tin-plating Tin-plating is carried out mainly to permit or improve soldering (soft-solder).

Simultaneously serves as corrosion protection. Subsequent heat treatment not possible.Anodizing When aluminum is anodized (electrolytic oxidation), a coating which provides corrosion protection is produced also prevents tarnishing. Practically any color can be produced for decorative purposes.

Further surface treatments

Process Details

Hot-dip galvanizing Immersion in molten zinc with a temp. of about 440 C to 470 C. Thickness of coating not less than 40 m.Finish dull and rough. Color change possible after a certain time.Very good corrosion protection. Can be used for thread parts from M8. Threads need to be over or undercut toassure proper thread mating.

Zinc flake coatings Geomet

Delta-Tone /Delta-Protekt

Zinc flake coatings are excellent for high strength components with tensile strength of Rm 1000 N/mm2 (Property class 10.9, Hardness 320 HV).

This process practically eliminates the possibility of hydrogen embrittlement. Temperature resistant 300 C.Can be applied to size M4 and up.

Mechanical plating Mechanical /chemical process. The degreased parts are placed in a drum with powdered zinc and glass pellets.The pellets serve to transfer the zinc powder to the surface to be treated.

Black oxidizing ofStainless steel

Chemical process. Corrosion resistance from A1 to A4 may be low.For decorative purposes.

Black oxidizing Chemical process, bath temperature about 140 C.For decorative purposes; merely slight corrosion protection.

Phosphate(bonderizing, parkerizing,atramentizing)

Only slight corrosion protection. Good undercoat for painting. Grey to grey-black appearance.Better corrosion protection oiled.

Waterproofing / sealing Particularly with nickel-plated parts, subsequent treatment in dewatering fluid with the addition of wax

may seal the micropores with wax. Significantly improves the corrosion resistance.The wax film is dry and invisible.Baking Following electrolytic or pickling treatment, high tensile strength steel parts (from Rm 1000 N/mm2, corresponding to

320 HV) can become brittle due to hydrogen absorption (hydrogen embrittlement). This embrittlement increases forcomponents with small cross sections. Part of the hydrogen can be eliminated by baking between 180 C and 230 C(below tempering temperature). Experience indicates that this is not guaranteed 100 %.Baking for >4 hrs must immediately be carried out after pickling and after galvanic treatment.

Tribological coating1)(Solid lm lubricants)

These coatings provide a friction reducing and wear resistant film.Reduce galling tendency.

Waxing Provide a lubrication layer, reduces driving torque and thread-forming screws.

1) Bossard ecosyn -lubric Bossard ecosyn -lubric tribological dry coating is a non-electrolytically applied, thin layered coating with integrated lubricating properties and additionalcorrosion protection. The coating consists of a composition of fluoropolymers and organic submicroscopic solid lubricant particles, which are dispersed incarefully selected synthetic resin blends and solvents. The AFC coating (Anti-Friction-Coating) creates a smooth film, which balances all unevenness of thesurface thereby optimising friction under extreme loads and working conditions. The synthectic resin in turn ensures better corrosion protection.



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Arrangement, design, assembly

Length of engaged thread

Recommended minimum lengths of engaged thread in cutted internal threads on components

from information provided by manufacturers, based on trail values M6 to M16

Where screws have to be screwed into internal threads andwhere full load-bearing capacity is required, then minimumlengths of engaged thread have to be defined which depend onthe strength of the material from which the component is made.

There is normally less flexibility compared with standard nuts,so that when tightening up there is no need to worry about anyresulting enlargement which migh

catalogo brossard parafusos

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