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Sigma Fasteners, Inc. Section 15

DESCRIPTION PAGEUnified Inch Screw Threads 15-1 to 15-5

ASTM & SAE Grade Markings for Steel Bolts & Screws 15-6

Platings & Coatings for Fasteners 15-7 to 15-8

Hex Cap Screws SAE J429 15-9 to 15-11

Steel Bar Weights 15-12

Weight Multiplier for Various Materials 15-13

Material Selection Chart 15-14


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Sigma Fasteners, Inc. Section 15 Page 5

ASTM AND SAE GRADE MARKINGSFOR STEEL BOLTS AND SCREWS

GradeMarking

Specification MaterialBold & Screw

Size (In.)Yield

PSI

Ult. TensileStrengthMin PSI

SAE-Grade 1

Low Carbon Steel1018-1022 Steel

1/4 thru 1-1/2 33,000 60,000

Grade AASTM-A307

1/4 thru 1-1/2over 1-1/2 thru 4

33,000----

60,00055,000

SAE-Grade 21/4 thru 3/4

over 3/4 thru 1-1/255,00033,000

74,00060,000

SAE-Grade 5Medium Carbon Steel

Quenched & Tempered1038 Steel

1/4 thru 1-1/2over 1-1/2 thru 4 85,00074,000 120,000105,000

ASTM-A4491/4 thru 1

over 1 thru 1-1/2over 1-1/2 thru 3

85,0007400055,000

120,000105,00090,000

ASTM-A325Medium Carbon Steel

Quenched & Tempered1038 Steel

1/2, 5/8, 3/47/8, 1

1-1/8 thru 1-1/2

85,00078,00074,000

120,000115,000105,000

ASTM-A354Grade BD

Alloy Steel,Quenched & Tempered

4140/4340 Alloy Steel

1/4 thru 2-1/2over 2-1/2 thru 4

130,000115,000

150,000140,000

ASTM-A354Grade BC

Alloy Steel,Quenched & Tempered4140/4145 Alloy Steel

1/4 thru 2-1/2over 2-1/2

109,00099,000

125,000115,000

ASTM-A193Grade B7

Alloy Steel,Quenched & Tempered

2-1/2 & under2-1/2 thru 4

105,00095,000

125,000115,000

SAE-Grade 8Medium Carbon Alloy Steel

Quenched & Tempered1/4 thru 1-1/2 120,000 150,000

ASTM-A490Alloy Steel,

Quenched & Tempered1/2 thru 2-1/2

over 2-1/2 thru 4120,000105,000

150,000140,000


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PLATINGS AND COATINGS FOR FASTENERS

Cadmium Plating (ASTM B766)

An electrolytically deposited, silver-gray plating which provides exceptionally good protection againstcorrosion, particularly in a salt atmosphere. Chromate Clear Dip is a protective film dip applied afterelectroplating, and gives additional corrosion protection and a bright, shiny appearance which resists

staining and finger marks. Cadmium is a known carcinogen, and has been banned in many countries.Commercial grades of cadmium plating are typically applied a minimum of 5 microns thick(.0002).Cadmium plating with a chromate dip must not show white corrosion products at 96 hours of salt spraytesting per ASTM B117.

Zinc Electroplating (ASTM B633)Zinc electroplating is also a protective coating against corrosion, blue gray in color, non-toxic, and can beused around food. Zinc plating performs better than cadmium in an industrial atmosphere, but not in asalt atmosphere. A clear Chromate dip is a protective film applied after electroplating, adding corrosionprotection. At Sigma, we also use a silicon dip, to aid in assembly. Commercial grades of zinc

electroplating are typically applied a minimum of 5 microns thick (.0002). Zinc electroplating with achromate dip must not show base metal corrosion products at 96 hours of salt spray testing per ASTMB117, but may show white corrosion at the edges.

Thickness conversion factors: microns x .0394=mils, mils x 25.4=microns, mils x .0254=millimeters,mils x .001=inches

Chromate DipsClear chromate dip as used by Sigma is applied to all zinc plated parts unless otherwise requested. We

use an excellent product produced by MacDermid, which contains no hexavalent chrome.

Olive Drab Dichromate- Electroplated work is dipped in solution of chrome, nitric and acetic acids and adye. This produces additional corrosion resistance, and is thicker than standard chromate dips.

Yellow Iridescent Dichromate Electroplated work is dipped in solution of sodium dichromate, takes onsurface film of basic chromium chromate which resists corrosion. Finish is yellow to brown in color.

BakingParts to be electroplated that are RC38 or higher in hardness, should be further processed to relievehydrogen embrittlement. This process should include baking at 375 deg. F for 8 hours or more within 4hours of the plating process. If the parts are over 40 RC, the baking should be for 24 hours minimum.The baking should be done before the chromate treatment. The parts are re-dipped in acid very briefly toreactivate the surface prior to chromating.

Phosphating

Supplementary Phosphate Zinc-plated parts are dipped in a solution of acid phosphates, and catalyticagents at 200 degrees F. Adherent, porous coating makes an excellent bond for paint or oil, and isperformed on all Sigma parts to be coated.

Several types of phosphate coatings are available: manganese, zinc, and iron. At Sigma, we prefer zincphosphate as the best preparation for coating.

Black OxideBlack oxide is a thin film of iron oxide formed on the metal. It will not chip, peel, crack, or crumble. Thepleasing finish provides only mild rust protection.


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PassivationPassivation gives stainless steels added resistance to corrosion. The nitric acid or sodium dichromate dipremoves any imbedded metal particles on the surface, and leaves a protective film of stainless only, to

prevent rusting.

Hot Dip Galvanizing (ASTM A153):

Hot dip zinc galvanizing is available for many fasteners. Threads in the nuts must be tapped oversizedafter galvanizing, or the parts will not assemble. This coating is very effective in salt atmosphere becauseit is applied approximately 2 mils thick. Because of the need to tap the nuts after galvanizing, the insideof the nut forms corrosion that will not allow disassembly after a period of time.

Sigma does not recommend Hot Dip Galvanizing for medium to high strength alloy parts used in theproduction of oil and gas, because of the chance of hydrogen embrittlement, and the tendency for thethickness to vary, causing uneven torque readings upon application.

Molybdenum Disulfide

Moly coating is typically used as a bonded lubricant, and has some corrosion resistance. It is spraycoated to a dry film thickness of .4 to .7 mil, and cured in ovens.

Sermagard 1105 (ASTM F1428)

Sigma Fasteners is a licensed applicator for Sermagard products. 1105 is a ceramic-metallic sprayedbasecoat that at 1 mil of thickness or more affords 3000-4000 hours of ASTM B117 salt spray resistance,

with an appropriate topcoat. It can be used at high temperatures. It is extremely effective in saltatmospheres. The Sermagard 1105 process involves curing at high temperatures (Minimum of 750 deg.F) and subsequent burnishing with appropriate blast media to achieve conductivity. Sermagard 1105

contains aluminum flake.

Sermagard 1280Sermagard 1280 is a fluorocarbon topcoat, which when applied to Sermagard 1105 basecoat gives

superior corrosion resistance and UV protection.

Xylan 1000 SeriesXylan is a fluoropolymer topcoat manufactured by Whitford Corporation, which in the 1014 and 1070coatings afford high lubricity (co-efficient of friction as low as .02), and corrosion resistance ofapproximately 1000 hours(ASTM B117) when applied over phosphate, and up to 2000 hours whenapplied over electroplating. These are solvent based thin film topcoats. These Xylan products have amaximum operating temperature ranging up to 500 deg. F.

Xylan 1000 and 1400 series may also be applied over other basecoats, for added corrosion protection.

Xylan 1400 series:

The 1400 series coatings by Whitford (typically 1424), are low voc coatings. They have a coefficient offriction of .05 to .10, and a maximum constant operating temperature of 400 deg. F. The corrosionresistance of the 1400 series is approximately 1500 hours, when applied over a suitable basecoat such as

zinc electroplating.

Sigma also applies coatings from other manufacturers, per customer specifications. Examples of other

coating products we apply: Everslik by EM CoatingsInorganic ZincMagnigard


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Other ASTM Specifications commonly used for fasteners

A 307 Low Carbon Steel Externally and Internally Threaded Standard FastenersA 325 High Strength Steel Bolts for Structural Steel Joints, including Suitable Nuts and Plain HardenedWashers

A 449 Quenched and Tempered Steel Bolts and Studs, Grade 5A 453 High Temperature Bolting Materials, Age hardenedA 354 Quenched and Tempered Alloy Steel Bolts and Studs with Suitable Nuts Grades BC and BDA 490 High Strength Alloy Steel Bolts for Structural Steel Joints, including Suitable Nuts and PlainHardened WashersA 540 Alloy Bolting Material for Special ApplicationsA 563 -- Nuts of Carbon and Alloy SteelA 564 Age Hardening stainless steel (17-4, etc)A 574 Alloy Steel Socket Head Cap ScrewsF 593 Stainless Steel Bolts, Hex Cap Screws and Studs


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SAE SpecificationsJ 429c Mechanical and Quality Requirements for Threaded Fasteners

HEX CAP SCREWS SAE J429

Mechanical & Quality Requirements for Externally Threaded Fasteners

Proof Load & Tensile Requirementsa

Nominal

Diamof Product

& Threadsper In.

StressArea

Sq. In.

Grade 2 Grade 5 Grade 8

ProofLoadLb.

TensileStrengthMin Lb.

ProofLoadLb


ProofLoadLb


Coarse Thread Series -- UNRC

No. 1/4-

20 0.0318 1.750 2.350 2.700 3.800 3.800 4.7505/16-18 0.0524 2.900 3.900 4.450 6.300 6.300 7.8503/8-16 0.0775 4.250 5.750 6.600 9.300 9.300 11.600

7/16-14 0.1063 5.850 7.850 9.050 12.800 12.800 15.9001/2-13 0.1419 7.800 10.500 12.100 17.000 17.000 21.3009/16-12 0.182 10.000 13.500 15.500 21.800 21.800 27.300

5/8-11 1.226 12.400 16.700 19.200 27.100 27.100 33.9003/4-10 0.334 18.400 24.700 28.400 40.100 40.100 50.1007/8-9 0.462 15.200 27.700 39.300 55.400 55.400 69.3001-8 0.606 20.000 36.400 51.500 72.700 72.700 90.9001-1/8-7 0.763 25.200 45.800 56.500 81.100 91.600 114.4001-1/4-7 0.969 32.000 58.100 71.700 101.700 116.300 145.400

1-3/8-6 1.155 38.100 69.300 85.500 121.300 138.600 173.2001-1/2-6 1.405 46.40 84.300 104.000 147.500 168.600 210.800

Fine Thread Series UNRF

No. 1/4-28

0.0364 2.000 2.700 3.100 4.350 4.350 5.450

5/16-24 0.0580 3.200 4.300 4.900 6.950 6.950 8.7003/8-24 0.0878 4.800 6.500 7.450 10.500 10.500 13.2007/16-20 0.1187 6.550 8.800 10.100 14.200 14.200 17.8001/2-20 0.1599 8.800 11.800 13.600 19.200 19.200 24.0009/16-18 0.203 11.200 15.000 17.300 24.400 24.400 30.4005/8-19 0.256 14.100 18.900 21.800 30.700 30.700 38.4003/4-16 0.373 20.500 27.600 31.700 44.800 44.800 56.000

7/8-14 0.509 16.800 30.500 43.300 61.100 61.100 76.4001-12 0.663 21.900 39.800 56.400 79.600 79.600 99.4001-14 uns 0.679 22.400 40.700 57.700 81.500 81.500 101.900

1-1/8-12 0.856 28.200 51.400 63.300 89.900 102.700 128.4001-1/4-12 1.073 35.400 64.400 79.400 112.700 128.800 161.0001-3/8-12 1.315 43.400 78.900 97.300 138.100 157.800 197.200

1-1/2-12 1.581 52.200 94.900 117.000 166.000 189.700 237.200


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Suggested assembly torques for hex cap screws per SAE J429 CAUTION -- Seenotes below

CapScrewDiam

Grade 2 Grade 5 Grade 8Minimum

Yield

Strength

Torque(ft-lb)

MinimumYield

Strength

Torque(ft-lb)

MinimumYield

Strength

Torque(ft-lb)

UNRC UNRF UNRC UNRF UNRC UNRF

57,000 6 7 92,000 10 11 130,000 14 15

5/16 57,000 12 14 92,000 20 22 130,000 28 313/8 57,000 22 25 92,000 36 40 130,000 50 60

7/16 57,000 35 39 92,000 57 64 130,000 80 90 57,000 54 61 92,000 90 100 130,000 125 1409/16 57,000 77 87 92,000 125 140 130,000 180 200

5/8 57,000 107 122 92,000 175 200 130,000 240 280 57,000 190 212 92,000 310 340 130,000 430 480

7/8 36,000 193 216 92,000 500 550 130,000 700 7701 36,000 290 320 92,000 740 810 130,000 1050 11501-1/8 36,000 410 470 81,000 930 1040 --- --- ---1-1/4 36,000 580 645 81,000 1300 1440 --- --- ---1-3/8 36,000 760 870 81,000 1700 1900 --- --- ---1-1/2 36,000 1010 1115 81,000 2270 2550 --- --- ---

General formula for calculating torque. Torque (in.-lb) = 0.2 x nominal diameter meter of screw x load

(b) where load is 80% of yield strength expressed in pounds. not psi. Torque for bolts with nuts may beslightly higher. Tension induced in a cap screw may be checked by measuring overall length before

torquing and then under torque load. The crew stretches 0.001 in. per in. of screw length for each30.000 psi. induced tension. Applies only to loads below the yield point. Torque suggestions in the abovetable are calculated in accordance with a standard formula for cap screws. It is based on the assumption

that the screws and the internal threads into which they are rotated are free of excessive rust, dirt orlubricant. and that the threads have been properly formed within standard tolerances. Galvanizing orplating will upset the relationship between torque and tension upon which the table is based. Suchvariations of thread condition can cause the suggested torque values to vary by as much as 25%. Hot-galvanized zinc coatings may loosen and pack into the thread clearances causing galling of threads andthe possibility of broken bolts. CAUTION: The information in this table is offered due to repeated requestsby customers for such data. We suggest, in order to achieve adequate tightening and safe results, thatpersonnel using the torque control technique should be carefully trained in the theory and methods oftightening. Bolts that have been overloaded too far beyond their proof load -- or if threads have beenseriously distorted during tightening -- should be replaced.


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STEEL BAR WEIGHTS

NOMINAL RD BAR THREADED BAR HEX BAR

DIA INCH FOOT INCH FOOT INCH FOOT

1/8" 0.0035 0.0420 0.0038 0.0456

3/16" 0.0078 0.0936 0.0087 0.1044

1/4" 0.0139 0.1668 0.0453 0.5436

5/16" 0.0218 0.2616 0.0240 0.2880

3/8" 0.0313 0.3756 0.0345 0.4140

7/16" 0.0425 0.5100 0.0470 0.5640

1/2" 0.0557 0.6684 0.0438 0.525 0.0613 0.7356

9/16" 0.0704 0.8448 0.0777 0.9324

5/8" 0.0869 1.0428 0.0695 0.834 0.0958 1.1496

11/16" 0.1052 1.2624 0.1161 1.3932

3/4" 0.1252 1.5024 0.0991 1.189 0.1380 1.6560

13/16" 0.1469 1.7628 0.1620 1.9440

7/8" 0.1703 2.0436 0.1405 1.686 0.1878 2.2536

15/16" 0.1956 2.3472 0.2157 2.5884

1" 0.2225 2.6700 0.1843 2.211 0.2454 2.9448

1 1/8" 0.2817 3.3804 0.2354 2.825 0.3106 3.7272

1 " 0.3477 4.1724 0.2993 3.591 0.3834 4.6008

1 3/8" 0.4208 5.0496 0.3671 4.405 0.4639 5.5668

1 " 0.5007 6.0084 0.4419 5.303 0.5521 6.6252

1 5/8" 0.5876 7.0512 0.5238 6.285 0.6479 7.7748

1 " 0.6815 8.1780 0.6124 7.349 0.7515 9.0180

1 7/8" 0.7823 9.3876 0.7080 8.496 0.8627 10.3524

2" 0.8901 10.6812 0.8106 9.727 0.9815 11.7780

2 " 1.1266 13.5192 1.0367 12.44 1.2422 14.9064

2 " 1.3908 16.6896 1.2900 15.48 1.5336 18.4032

2 " 1.6829 20.1948 1.5867 19.04 1.8557 22.2684

3" 2.0028 24.0336 1.8867 22.64 2.2084 26.5008

3 " 2.3508 28.2096 2.2308 26.77 2.5918 31.1016

3 " 2.7251 32.7012 2.5967 31.16 3.0058 36.0696

3 " 3.1292 37.5504 3.4506 41.4072

4" 3.5608 42.7296 3.9260 47.1120


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WEIGHT MULTIPLIERS:

BRASS 0.364

HASTELLOY "B" 1.085

HASTELLOY "C" 1.187

HASTELLOY "G/G3" 1.139

HASTELLOY "X" 1.058

INCOLOY 800/800H 1.058

INCOLOY 825 1.012

INCONEL 600 1.037

INCONEL 625 1.074

INCONEL 718 1.082

INCONEL X-750 1.029

MONEL 400/405 1.053

MONEL K-500 1.078

NAVAL BRASS 1.074

NICKEL 200/201 1.134

SILICON BRONZE 1.110

TANTALUM 2.142

TITANIUM 0.582

TOOL STEEL 1.000

WASPALLOY 1.057

ZIRCONIUM 0.835

300 SERIES S/S 1.011

410 S/S 0.989

660 S/S 1.070

904-L 1.026


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MATERIALS SELECTION

Suggested materials for use in various temperatures and atmospheres typically encountered in theenergy industry

ASTMDesign-

tionGrade

ServiceTemp-eratureRange

Strength and Ductility

SuitableNuts

(ASTM/Grade)

TensileMin.psi

YieldReduction

of AreaR/A

Elong-tionEL

AlloyType

AISI

ASTM A-

193B7

High Temp.

from 0 480C

125,000 100,000 50 16 Cr-Mo (4140) A194 Gr 2H

ASTM A-

193B16

High Temp.from 0

550C

125,000 105,000 50 18 Cr-Mo V (4140M) A194 Gr 4

ASTM A-

193B7M

High Temp.from 0

450C

100,000 80,000 50 18 Cr-Mo (4140)A194 Gr

2HM

ASTM A-320

L7Low Temp.

-100C125,000 105,000 50 16 Cr-Mo (4140)

A194 Gr 4orA194 Gr 7

ASTM A-193

B5 Up to 815C 100,000 80,000 50 16 5% Cr (501) A194 Gr 3

ASTM A-193

B6 Up to 450C 110,000 85,000 50 16 13% Cr (410) A194 Gr 6

ASTM A-193

B8Low Temp.

-200 650C75,000 30,000 50 30

18% CR 8% Ni

(304) A194 B8

ASTM A-193

B8MLow Temp.

-200 750C75,000 30,000 50 30

16%Cr 10% Ni

(316) A194 B8M

ASTM A-320

B8Low Temp.

-200 650C75,000 30,000 50 30

18% Cr 8% Ni

(304) A194 B8

ASTM A-320

B8MLow Temp.

-200 750C75,000 30,000 50 30

16% Cr 10% Ni

(316) A194 B8M

ASTM A-320

B8TLow Temp.

-200 650C75,000 30,000 50 30 13% Cr (321) A194 B8T6

ASTM A-320 B8C Low Temp.-200 650C 75,000 30,000 50 30 18% CR 8% Ni (347) A194 B8C

ASTM A-193

B8Mclass 2

Low Temp.-200 650C

125,000 100,000 35 1216% Cr 10% Ni

(304) A194 B8C

ASTM A-453

660High Temp.up to 750C

130,000 85,000 18 15High IronSuperalloy

660 (A286) A453 600

ASTM A-564

(cond. 900)(cond.1100)

630Med Temp.

up to 316C190,000140,000

170,000115,000

4045

1014

PrecipitationHardening

STST630 (17-4) A564 630

ASTM B-

408

800

800H

High Temp.540C

815C

80,000 35,000 25 Incoloy --- ASTM B408

ASTM B-164

405High Temp.to 815C

85,000 50,000 15 Monel --- ---

ASTM B-

164K500

High Temp.

650C -423C

Low Temp.650 C 253C

100,000 70,000 35 Monel --- ---

600, 625,718, x750

ASTM

B446,B637

High Temp.

from 850C 1090C

100,000 80,000 30

Nickel

Superalloy(Inconel)

--- ---

B, C, XHigh Temp.

to 850C170,000 115,000 30

Nickel

Superalloy(Hastalloy)

--- ---

Incoloy 925High Temp.to - 1000C

176,000 120,000 40 24Nickel Iron

Chrome--- ---

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