bolt length hsb

Specifying Bolt Length for High-Strength Bolts

CHARLES J. CARTER

INTRODUCTIONTwo tables that are useful in determining the proper boltlength for high-strength bolts are provided in the AISCManual of Steel Construction:1 Table 8-2, which includesconstants to be added to the grip and washer thickness(RCSC Specification Table C22 is the basis for theseconstants) and a table in Figure 8-3, which indicates theouter-ply thickness required to exclude the threads from thefaying surface of the connection. While it is a simpleoperation to select bolt lengths using these tables, therepetitive calculation becomes somewhat tedious and couldbe simplified.

In this paper, a design aid is presented for the selectionof high-strength bolt lengths for bearing (snug-tightenedand fully tensioned) and slip-critical connections. Nominalbolt lengths are tabulated based upon the grip for ¾-in.,7/8-in., 1-in., and 1 1/8-in. diameter ASTM A325 and A490bolts with zero, one, or two 5/32-in.-thick ASTM F436 flatwasher(s) and an ASTM A563 nut; bevelled washers arenot considered in this paper. Additionally, the outer-plythickness required when it is desired to exclude the threadsfrom the shear plane is tabulated. Example problems areincluded to illustrate use of the table. The following topicsare also briefly addressed in this paper: (1) tolerances onbolt length, nut thickness, and washer thickness; (2) threadrun-out, stick-through requirements, and risk of jammingthe nut; (3) washer requirements; and, (4) excluding threadsfrom the shear plane of the connection.

MINIMUM BOLT LENGTH

The minimum possible length of high strength bolts iscalculated by summing the nominal grip, the nominalthickness of washer(s), and the appropriate value fromTable C2 of the Specification for Structural Joints UsingASTM A325 or A490 Bolts.2 Values in RCSC SpecificationTable C2 provide for the nominal thickness of the heavyhex nut and the following tolerances: (1) the minustolerance on bolt length; (2) the plus tolerance on washerthickness; and (3) the plus tolerance on nut thickness. Byone order of magnitude, the tolerance on bolt length is themost significant; see Appendix. Taking the worst caseaccumulation of these three tolerances, Table 1 illustratesthat the values in RCSC Specification Table C2 are

Charles J. Carter is senior staff engineer, American Institute of SteelConstruction, Inc., Chicago, IL.

conservative for all bolts less than or equal to 6-in. long.For bolts longer than 6 inches, the values are conservativefor 1 1/8-in. diameter bolts and negligibly unconservative(within 3/64-in.) for ¾-in., 7/8-in., and 1-in. diameter boltsassuming. This is considered to be negligible because theworst-case accumulation of tolerances assumed is astatistical improbability. The nominal bolt length is thenselected as the next larger increment based on the minimumpossible length. As is general industry practice, for boltlengths less than 5 inches, a nominal length increment of¼-in. is used; otherwise, a nominal length increment of ½-in. is used.

In the installed condition, even if the nominal length isexactly equal to the minimum possible length, the end ofthe bolt will be at least flush with the end of the nut. Someproject specifications include a stick-through requirement(minimum protrusion of the bolt point beyond the nut).However, because the threaded length for any given boltdiameter is constant regardless of the bolt length, a stick-through requirement may require a longer bolt and therebyincreases the risk of jamming the nut on the thread run-out.Because a stick-through requirement does not improve theperformance of the bolt, its specification is discouraged.

In Table 2, bolt lengths L have been tabulated for ¾-in.,7/8-in., 1-in., and 1 1/8-in. diameter ASTM A325 and A490bolts with zero, one, or two 5/32-in.-thick ASTM F436washer(s). Because 8 inches is generally the maximumstock bolt length available except by special order,tabulated values for combinations requiring longer lengthshave been omitted. The tabulated values are valid forconventional high-strength bolts and alternative designfasteners, such as tension-control or twist-off bolts. Ifdirect tension indicator devices are to be used, the tabulatedvalues remain useful if the thickness of such devices isconsidered to be part of the grip.

In many cases when one washer is used, the minimumpossible bolt length exceeds a nominal length increment by1/32-in. For example, a ¾-in. diameter bolt with one 5/32-in.-thick washer and a 7/8-in. grip would require a length of

in.2132

5

8

732

1=++

where 1 inch is the value from RCSC Specification TableC2. In this and other such cases, the tabulated minimumbolt length has been rounded down to the shorter nominallength increment because 1/32-in. is negligible. In all othercases, the tabulated minimum bolt length is rounded to thenext longer nominal length increment.

ENGINEERING JOURNAL / SECOND QUARTER / 1996 43

Shading in the table indicates that the combination ofgrip, bolt length, and number of washers is such that the nutmay jamb on the thread run-out; this occurs only for boltslonger than 5 inches (i.e., when ½-in. length increments areused). The use of additional washers, which may alsorequire a longer bolt, is a common solution. Jamming mayoccur when the bolt length minus the threaded lengthexceeds the grip plus the minimum thickness of washer(s)minus an allowance for the elongation of the bolt duringtensioning. For most bolts, a nut rotation of one-half totwo-thirds from snug-tight is required to achieve fulltensioning; longer bolts may require one full turn.Conservatively assuming one full turn, and because the nutsurface is countersunk by approximately one third of onethread pitch, the appropriate allowance (see Appendix) forelongation of the bolt during tensioning is two-thirds of onethread pitch;3 this will be conservative for snug-tightenedbolts, which may have significantly less elongation.

WASHER REQUIREMENTS

RCSC Specification Section 7(c) indicates the cases inwhich 32

5 -in.-thick ASTM F436 washers must be used withASTM A325 and A490 bolts. Such washers are notrequired for these high-strength bolts in standard,oversized, and short-slotted holes except:

1. under the turned element when the bolt is fullytensioned by the calibrated wrench method.

2. under the head and nut when ASTM A490 bolts areused in combination with material with a specifiedyield point below 40 ksi.

3. to cover an oversized or short-slotted hole in anouter ply. For ASTM A490 bolts over 1 inch indiameter through an oversized or short-slotted holein an outer ply, the washer must be 16

5 -in.-thick;

two 325 -in.-thick washers do not meet this

requirement.

Some alternative design fasteners provide a bearing circleon the bolt head and/or nut of diameter equal to or greaterthan the diameter of an ASTM F436 washer. When suchfasteners are used, the need for washers in cases 1 and 2above is eliminated.

When high-strength bolts are used through long-slottedholes in an outer ply, a plate washer with standard holesthat completely covers the slot must be provided; the platewasher must be made from structural grade material with aminimum thickness of 16

5 -in., but need not be hardened.For ASTM A490 bolts over 1 inch in diameter throughlong-slotted holes in an outer ply, single 16

5 -in.-thick

ASTM F436 washers must be used; two 325 -in.-thick

washers do not meet this requirement.

EXCLUDING THREADS FORBEARING X CONNECTIONS

The minimum thickness t of the outer connected ply closestto the nut to exclude threads from the shear plane of the

connection has been tabulated in Table 2. It is calculated asthe grip plus the threaded length minus the bolt length. Adash indicates that, for the given grip, the threads will beexcluded regardless of the actual thickness of the plyclosest to the nut (i.e., t ≤ 0). A common solution when it isdesired to exclude the threads but the minimum thickness isnot present is to use a longer bolt with additional washer(s)under the nut. Nominal dimensions are used in thiscalculation for two reasons: (1) RCSC SpecificationCommentary Section C2 permits thread run-out into theshear plane; and, (2) the control dimension in boltthreading is the distance from the underside of the bolthead to the first useable thread; i.e., the bolt underlengthtolerance is absorbed in the threaded length. In calculatingthe tabulated values of t, washers (if used) are assumed tobe installed under the nut. If washer(s) are present underthe bolt head, their thickness must be added to the tabulatedvalue of t. When a dash is shown and washer(s) are to beplaced under the bolt head, the value of t can be determinedas indicated above; alternatively, the washer thickness maybe considered as part of the grip.

A common rule of thumb2 can be generalized from thetabulated values for minimum outer-ply thickness. With nowashers, the threads will always be excluded from the shearplane (regardless of the grip) for ¾-in. and 8

7 -in. diameter

bolts if the outer ply thickness is not less than 83 -in.; the

same is true for 1-in. and 811 -in. diameter bolts if the outer

ply thickness is not less than ½-in. With one washer underthe nut, these values may be reduced by 8

1 -in. Because thisrule of thumb is based upon the worst case combination ofgrip and bolt length, reference to the tabulated values forlesser outerply thicknesses will often be beneficial.

A supplementary provision has been added to ASTMA325 for full-length threading (ASTM A325T). Thisprovision may be specified for ASTM A325 bolts of lengthless than or equal to four times the bolt diameter only; thereis no similar provision in ASTM A490. Note that if ASTMA325T bolts are specified, it is impossible to exclude thethreads from the shear plane. Thus, for these bolts, thetabulated values of t are meaningless.

ILLUSTRATIVE EXAMPLES

The following examples illustrate the use of Table 2.

Example 1

Given:

Select the bolt length for ¾-in. diameter ASTM A325-Nbolts in standard holes in a 83 -in. single-plate connection

supporting a W21×50 beam (nominal tw= 83 -in.).

Solution:

The grip is 83 + 8

3 = ¾-in. From Table 2, for ¾-in.diameter bolts with zero washers, use 1¾-in. bolt length.

44 ENGINEERING JOURNAL / SECOND QUARTER / 1996

Example 2

Given:

Select the bolt length for ¾-in. diameter ASTM A325-Xbolts in standard holes in a double-angle connection with2L5×3× 16

5 supporting a W27×84 beam (nominal tw = 167 -

in.).

Solution:

The grip is 165 + 16

7 + 165 = 16

11 in. From Table 2, for ¾-in. diameter bolts with zero washers, try 2¼-in. bolt length.Also from Table 2, the minimum thickness of the plyclosest to the nut to exclude the threads is 16

3 -in. Since this

is less than the 165 -in. angle thickness, use 2¼-in. bolt

length.

Example 3

Given:

Select the bolt length for fully tensioned ¾-in. diameterASTM A325-N bolts connecting a ½-in.-thick angle to aW14×500 column flange (nominal tw = 3½ in.). Thecalibrated wrench method will be used to tension the boltsrequiring one washer under the turned element.

Solution:

The grip is ½ + 3½ = 4 in. From Table 2, for ¾-in. diameterbolts with one washer, the table cell is shaded, indicatingthat this combination or grip, number of washers, and boltlength is such that the nut may jamb on the thread run-out.Therefore, try two washers. From Table 2, for ¾-in.diameter bolts with two washers, use 5½-in. bolt length.

Example 4

Given:

Select the bolt length for 87 -in. diameter ASTM A490-Nbolts in standard holes in an extended end-plate momentconnection (1-in. thick) to a W14×132 column flange(nominal tf = 1 in.). The column and end-plate material areASTM A572 grade 50 material. Bolts will be tension-control-type alternative design fasteners.

Solution:

The grip is 1 + 1 = 2 in. From Table 2, for 87 -in. diameter

bolts with zero washers, use 3¼-in. bolt length.

REFERENCES

1. American Institute of Steel Construction, Manual of SteelConstruction—Load and Resistance Factor Design, Volume II—Connections, p. 8-11 and 8-18, Chicago, IL, 1994.

2. Research Council on Structural Connections, Load andResistance Factor Design Specification for Structural JointsUsing ASTM A325 or A490 Bolts, AISC, Chicago, IL, 1988.

3. Industrial Fasteners Institute, Fastener Standards, Sixth Ed.,IFI, Cleveland, OH, 1988.

APPENDIX

The following table is from the RCSC Specification.2

Table C2.To Determine Required Bolt

Nominal Bolt Size, inches Length Add to Grip, In inches

½ 1611

85

87

¾ 1

87

811

1 1¼

811 1½

1¼8

51

831 1¾

1½8

71

The following tables are summarized from FastenerStandards.3

Bolt length toleranceBolt length, in.

Dia., in. 6 or less over 6

¾ –0.19 –0.25

87 –0.19 –0.25

1 –0.19 –0.25

811 –0.25 –0.25

Washer thickness tolerancesWasher thickness, in.

Dia., in. Max. Nom. Min.

¾ 0.17732

5 (0.156) 0.122

87 0.177

325 (0.156) 0.136

1 0.17732

5 (0.156) 0.136

811 0.177

325 (0.156) 0.136

Nut thickness tolerancesNut thickness, in.

Dia., in. Max. Nom. Min.

¾ 0.75864

47 (0.734) 0.710

87 0.885

6455 (0.859) 0.833

1 1.01264

63 (0.984) 0.956

811 1.139

6471 (1.109) 1.079

Allowance for elongation due to full tensioningThreads Thread

Dia., in. per inch pitch, p, in. 2p/3¾ 10 0.100 0.067

87 9 0.111 0.074

1 8 0.125 0.084

811 7 0.143 0.096


Table 1.Bolt, Nut, and Washer Tolerances vs. RCSC Specification Table C2 Allowance

(all values in inches)

Bolts less than or equal to 6-in. long

Tolerances from Appendix RCSC Spec. Table C2 conservative by:

Number of washersBoltDiameter

RCSC Spec.Table C2

AllowanceNut

ThicknessBolt

UnderlengthNut

OverthickWasher

Overthick Zero One Two¾ 1

6447 0.19 0.024 0.021

643

321

641

87

811 64

55 0.19 0.026 0.02164

332

164

1

1 1¼64

63 0.19 0.028 0.02164

332

1 0

811 1½

6471 0.25 0.030 0.021

647

323

161

Bolts over 6-in. long

Tolerances from Appendix RCSC Spec. Table C2 conservative by:

Number of washersBoltDiameter

RCSCTable C2

NutThickness

BoltUnderlength

NutOverthick

WasherOverthick Zero One Two

¾ 164

47 0.25 0.024 0.021 − 164 − 1

32− 3

64

87

811 64

55 0.25 0.026 0.021 − 164 − 1

32− 3

64

1 1¼64

63 0.25 0.028 0.021 − 164 − 1

32− 3

64

811 1½

6471 0.25 0.030 0.021

647

323

161

Shading indicates that RCSC Specification Table C2 values result in negligibly unconservative bolt lengths.


Table 2.ASTM A325 and A490 Bolts with

zero, one, or two 325 -In.-thick washer(s)

¾-in. dia. 78 -in. dia.

no washers 1 washer 2 washers no washers 1 washer 2 washersGrip L , in. t, in. L , in. t, in. L , in. t, in. L , in. t, in. L , in. t, in. L , in. t, in.

½ 1½ 83 1¾ 1

8 2 — 1¾ ¼ 1¾ ¼ 2 —

169 1¾ 16

3 1¾ 316 2 — 1¾ 5

16 2 116 2 1

16

85 1¾ ¼ 1¾ ¼ 2 — 1¾ 3

8 2 18 2¼ —

1611 1¾ 16

5 2 116 2 1

16 2 316 2 3

16 2¼ —

¾ 1¾ 83 2 1

8 2¼ — 2 ¼ 2 ¼ 2¼ —

1613 2 16

3 2 316 2¼ — 2 5

16 2¼ 116 2¼ 1

16

87 2 ¼ 2 ¼ 2¼ — 2 3

8 2¼ 18 2½ —

1615 2 16

5 2¼ 116 2¼ 1

16 2¼ 316 2¼ 3

16 2½ —

1 2 83 2¼ 1

8 2½ — 2¼ ¼ 2¼ ¼ 2½ —

1611 2¼ 16

3 2¼ 316 2½ — 2¼ 5

16 2½ 116 2½ 1

16

811 2¼ ¼ 2¼ ¼ 2½ — 2¼ 3

8 2½ 18 2¾ —

1631 2¼ 16

5 2½ 116 2½ 1

16 2½ 316 2½ 3

16 2¾ —

1¼ 2¼ 83 2½ 1

8 2¾ — 2½ ¼ 2½ ¼ 2¾ —

1651 2½ 16

3 2½ 316 2¾ — 2½ 5

16 2¾ 116 2¾ 1

16

831 2½ ¼ 2½ ¼ 2¾ — 2½ 3

8 2¾ 18 3 —

1671 2½ 16

5 2¾ 116 2¾ 1

16 2¾ 316 2¾ 3

16 3 —

1½ 2½ 83 2¾ 1

8 3 — 2¾ ¼ 2¾ ¼ 3 —

1916 2¾ 16

3 2¾ 316 3 — 2¾ 5

16 3 116 3 1

16

158 2¾ ¼ 2¾ ¼ 3 — 2¾ 3

8 3 18 3¼ —

11116 2¾ 16

5 3 116 3 1

16 3 316 3 3

16 3¼ —

1¾ 2¾ 83 3 1

8 3¼ — 3 ¼ 3 ¼ 3¼ —

11316 3 16

3 3 316 3¼ — 3 5

16 3¼ 116 3¼ 1

16

178 3 ¼ 3 ¼ 3¼ — 3 3

8 3¼ 18 3½ —

11516 3 16

5 3¼ 116 3¼ 1

16 3¼ 316 3¼ 3

16 3½ —

2 3 38 3¼ 1

8 3½ — 3¼ ¼ 3¼ ¼ 3½ —

2 116 3¼ 3

16 3¼ 316 3½ — 3¼ 5

16 3½ 116 3½ 1

16

2 18 3¼ ¼ 3¼ ¼ 3½ — 3¼ 3

8 3½ 18 3¾ —

2 316 3¼ 5

16 3½ 116 3½ 1

16 3½ 316 3½ 3

16 3¾ —

Notes:1. Minimum bolt length calculated per RCSC Specification Table C22. Below 5-in. bolt length, minimum length increment is ¼-in.; otherwise, ½-in.3. When washer(s) are under bolt head, increase t by thickness of washer(s)4. Shaded cells indicate longer bolt and additional washers may be required to prevent nut from jamming on the thread run-out5. "—" indicates that threads are excluded regardless of ply thickness


Table 2.ASTM A325 and A490 Bolts

with zero, one, or two 532 -In.-thick washer(s)

1-in. dia. 118 -in. dia.


½ 1¾ ½ 2 ¼ 2¼ — 2 ½ 2¼ ¼ 2½ —9

16 2 516 2 5

16 2¼ 116 2¼ 5

16 2¼ 516 2½ 1

16

58 2 3

8 2 38 2¼ 1

8 2¼ 38 2¼ 3

8 2½ 18

1116 2 7

16 2¼ 316 2¼ 3

16 2¼ 716 2½ 3

16 2½ 316

¾ 2 ½ 2¼ ¼ 2½ — 2¼ ½ 2½ ¼ 2¾ —13

16 2¼ 516 2¼ 5

16 2½ 116 2½ 5

16 2½ 516 2¾ 1

16

78 2¼ 3

8 2¼ 38 2½ 1

8 2½ 38 2½ 3

8 2¾ 18

1516 2¼ 7

16 2½ 316 2½ 3

16 2½ 716 2¾ 3

16 2¾ 316

1 2¼ ½ 2½ ¼ 2¾ — 2½ ½ 2¾ ¼ 3 —

1116 2½ 5

16 2½ 516 2¾ 1

16 2¾ 516 2¾ 5

16 3 116

118 2½ 3

8 2½ 38 2¾ 1

8 2¾ 38 2¾ 3

8 3 18

1316 2½ 7

16 2¾ 316 2¾ 3

16 2¾ 716 3 3

16 3 316

1¼ 2½ ½ 2¾ ¼ 3 — 2¾ ½ 3 ¼ 3¼ —

1516 2¾ 5

16 2¾ 516 3 1

16 3 516 3 5

16 3¼ 116

138 2¾ 3

8 2¾ 38 3 1

8 3 38 3 3

8 3¼ 18

1716 2¾ 7

16 3 316 3 3

16 3 716 3¼ 3

16 3¼ 316

1½ 2¾ ½ 3 ¼ 3¼ — 3 ½ 3¼ ¼ 3½ —

1916 3 5

16 3 516 3¼ 1

16 3¼ 516 3¼ 5

16 3½ 116

158 3 3

8 3 38 3¼ 1

8 3¼ 38 3¼ 3

8 3½ 18

11116 3 7

16 3¼ 316 3¼ 3

16 3¼ 716 3½ 3

16 3½ 316

1¾ 3 ½ 3¼ ¼ 3½ — 3¼ ½ 3½ ¼ 3¾ —113

16 3¼ 516 3¼ 5

16 3½ 116 3½ 5

16 3½ 516 3¾ 1

16

178 3¼ 3

8 3¼ 38 3½ 1

8 3½ 38 3½ 3

8 3¾ 18

11516 3¼ 7

16 3½ 316 3½ 3

16 3½ 716 3¾ 3

16 3¾ 316

2 3¼ ½ 3½ ¼ 3¾ — 3½ ½ 3¾ ¼ 4 —

2 116 3½ 5

16 3½ 516 3¾ 1

16 3¾ 516 3¾ 5

16 4 116

2 18 3½ 3

8 3½ 38 3¾ 1

8 3¾ 38 3¾ 3

8 4 18

2 316 3½ 7

16 3¾ 316 3¾ 3

16 3¾ 716 4 3

16 4 316




with zero, one, or two 325 -in.-thick washer(s)



2¼ 3¼ 38 3½ 1

8 3¾ — 3½ ¼ 3½ ¼ 3¾ —

2 516 3½ 3

16 3½ 316 3¾ — 3½ 5

16 3¾ 116 3¾ 1

16

2 38 3½ ¼ 3½ ¼ 3¾ — 3½ 3

8 3¾ 18 4 —

2716 3½ 5

16 3¾ 116 3¾ 1

16 3¾ 316 3¾ 3

16 4 —

2½ 3½ 38 3¾ 1

8 4 — 3¾ ¼ 3¾ ¼ 4 —

2916 3¾ 3

16 3¾ 316 4 — 3¾ 5

16 4 116 4 1

16

2 58 3¾ ¼ 3¾ ¼ 4 — 3¾ 3

8 4 18 4¼ —

21116 3¾ 5

16 4 116 4 1

16 4 316 4 3

16 4¼ —

2¾ 3¾ 38 4 1

8 4¼ — 4 ¼ 4 ¼ 4¼ —

21316 4 3

16 4 316 4¼ — 4 5

16 4¼ 116 4¼ 1

16

278 4 ¼ 4 ¼ 4¼ — 4 3

8 4¼ 18 4½ —

21516 4 5

16 4¼ 116 4¼ 1

16 4¼ 316 4¼ 3

16 4½ —

3 4 38 4¼ 1

8 4½ — 4¼ ¼ 4¼ ¼ 4½ —

3116 4¼ 3

16 4¼ 316 4½ — 4¼ 5

16 4½ 116 4½ 1

16

318 4¼ ¼ 4¼ ¼ 4½ — 4¼ 3

8 4½ 18 4¾ —

3316 4¼ 5

16 4½ 116 4½ 1

16 4½ 316 4½ 3

16 4¾ —

3¼ 4¼ 38 4½ 1

8 4¾ — 4½ ¼ 4½ ¼ 4¾ —

3516 4½ 3

16 4½ 316 4¾ — 4½ 5

16 4¾ 116 4¾ 1

16

338 4½ ¼ 4½ ¼ 4¾ — 4½ 3

8 4¾ 18 5 —

3716 4½ 5

16 4¾ 116 4¾ 1

16 4¾ 316 4¾ 3

16 5 —

3½ 4½ 38 4¾ 1

8 5 — 4¾ ¼ 4¾ ¼ 5 —

3916 4¾ 3

16 4¾ 316 5 — 4¾ 5

16 5 116 5 1

16

358 4¾ ¼ 4¾ ¼ 5 — 4¾ 3

8 5 18 5½ —

31116 4¾ 5

16 5 116 5 1

16 5 316 5 3

16 5½ —

3¾ 4¾ 38 5 1

8 5½ — 5 ¼ 5 ¼ 5½ —

31316 5 3

16 5 316 5½ — 5 5

16 5½ — 5½ —

378 5 ¼ 5 ¼ 5½ — 5 3

8 5½ — 5½ —

31516 5 5

16 5½ — 5½ — 5½ — 5½ — 5½ —







2¼ 3½ ½ 3¾ ¼ 4 — 3¾ ½ 4 ¼ 4¼ —

2 516

3¾ 516

3¾ 516

4 116

4 516

4 516

4¼ 116

2 38

3¾ 38

3¾ 38

4 18

4 38

4 38

4¼ 18

2716

3¾ 716

4 316

4 316

4 716

4¼ 316

4¼ 316

2½ 3¾ ½ 4 ¼ 4¼ — 4 ½ 4¼ ¼ 4½ —

2916

4 516

4 516

4¼ 116

4¼ 516

4¼ 516

4½ 116

2 58

4 38

4 38

4¼ 18

4¼ 38

4¼ 38

4½ 18

21116

4 716

4¼ 316

4¼ 316

4¼ 716

4½ 316

4½ 316

2¾ 4 ½ 4¼ ¼ 4½ — 4¼ ½ 4½ ¼ 4¾ —

21316

4¼ 516

4¼ 516

4½ 116

4½ 516

4½ 516

4¾ 116

278

4¼ 38

4¼ 38

4½ 18

4½ 38

4½ 38

4¾ 18

21516

4¼ 716

4½ 316

4½ 316

4½ 716

4¾ 316

4¾ 316

3 4¼ ½ 4½ ¼ 4¾ — 4½ ½ 4¾ ¼ 5 —

3116

4½ 516

4½ 516

4¾ 116

4¾ 516

4¾ 516

5 116

318

4½ 38

4½ 38

4¾ 18

4¾ 38

4¾ 38

5 18

3316

4½ 716

4¾ 316

4¾ 316

4¾ 716

5 316

5 316

3¼ 4½ ½ 4¾ ¼ 5 — 4¾ ½ 5 ¼ 5½ —

3516

4¾ 516

4¾ 516

5 116

5 516

5 516

5½ —

338

4¾ 38

4¾ 38

5 18

5 38

5 38

5½ —

3716

4¾ 716

5 316

5 316

5 716

5½ — 5½ —

3½ 4¾ ½ 5 ¼ 5½ — 5 ½ 5½ — 5½ —

3916

5 516

5 516

5½ — 5½ 116

5½ 116

5½ 116

358

5 38

5 38

5½ — 5½ 18

5½ 18

5½ 18

31116

5 716

5½ — 5½ — 5½ 316

5½ 316

5½ 316

3¾ 5 ½ 5½ — 5½ — 5½ ¼ 5½ ¼ 6 —

31316

5½ 116

5½ 116

5½ 116

5½ 516

5½ 516

6 —

378

5½ 18

5½ 18

5½ 18

5½ 38

5½ 38

6 —

31516

5½ 316

5½ 316

5½ 316

5½ 716

6 — 6 —







4 5 38 5½ — 5½ — 5½ — 5½ — 5½ —

4 116 5½ — 5½ — 5½ — 5½ 1

16 5½ 116 5½ 1

16

4 18 5½ — 5½ — 5½ — 5½ 1

8 5½ 18 6 —

4 316 5½ 1

16 5½ 116 5½ 1

16 5½ 316 5½ 3

16 6 —

4¼ 5½ 18 5½ 1

8 6 — 5½ ¼ 5½ ¼ 6 —

4 516 5½ 3

16 5½ 316 6 — 5½ 5

16 6 — 6 —

4 38 5½ ¼ 5½ ¼ 6 — 5½ 3

8 6 — 6 —

4716 5½ 5

16 6 — 6 — 6 — 6 — 6 —

4½ 5½ 38 6 — 6 — 6 — 6 — 6 —

4916 6 — 6 — 6 — 6 1

16 6 116 6 1

16

4 58 6 — 6 — 6 — 6 1

8 6 18 6½ —

41116 6 1

16 6 116 6 1

16 6 316 6 3

16 6½ —

4¾ 6 18 6 1

8 6½ — 6 ¼ 6 ¼ 6½ —

41316 6 3

16 6 316 6½ — 6 5

16 6½ — 6½ —

478 6 ¼ 6 ¼ 6½ — 6 3

8 6½ — 6½ —

41516 6 5

16 6½ — 6½ — 6½ — 6½ — 6½ —

5 6 38 6½ — 6½ — 6½ — 6½ — 6½ —

5116 6½ — 6½ — 6½ — 6½ 1

16 6½ 116 6½ 1

16

518 6½ — 6½ — 6½ — 6½ 1

8 6½ 18 7 —

5316 6½ 1

16 6½ 116 6½ 1

16 6½ 316 6½ 3

16 7 —

5¼ 6½ 18 6½ 1

8 7 — 6½ ¼ 6½ ¼ 7 —

5516 6½ 3

16 6½ 316 7 — 6½ 5

16 7 — 7 —

538 6½ ¼ 6½ ¼ 7 — 6½ 3

8 7 — 7 —

5716 6½ 5

16 7 — 7 — 7 — 7 — 7 —

5½ 6½ 38 7 — 7 — 7 — 7 — 7 —

5916 7 — 7 — 7 — 7 1

16 7 116 7 1

16

558 7 — 7 — 7 — 7 1

8 7 18 7½ —

51116 7 1

16 7 116 7 1

16 7 316 7 3

16 7½ —







4 5½ ¼ 5½ ¼ 6 — 5½ ½ 6 — 6 —

4 116 5½ 5

16 5½ 516 6 — 6 1

16 6 116 6 1

16

4 18 5½ 3

8 5½ 38 6 — 6 1

8 6 18 6 1

8

4 316 5½ 7

16 6 — 6 — 6 316 6 3

16 6 316

4¼ 5½ ½ 6 — 6 — 6 ¼ 6 ¼ 6½ —

4 516 6 1

16 6 116 6 1

16 6 516 6 5

16 6½ —

4 38 6 1

8 6 18 6 1

8 6 38 6 3

8 6½ —

4716 6 3

16 6 316 6 3

16 6 716 6½ — 6½ —

4½ 6 ¼ 6 ¼ 6½ — 6 ½ 6½ — 6½ —

4916 6 5

16 6 516 6½ — 6½ 1

16 6½ 116 6½ 1

16

4 58 6 3

8 6 38 6½ — 6½ 1

8 6½ 18 6½ 1

8

41116 6 7

16 6½ — 6½ — 6½ 316 6½ 3

16 6½ 316

4¾ 6 ½ 6½ — 6½ — 6½ ¼ 6½ ¼ 7 —

41316 6½ 1

16 6½ 116 6½ 1

16 6½ 516 6½ 5

16 7 —

478 6½ 1

8 6½ 18 6½ 1

8 6½ 38 6½ 3

8 7 —

41516 6½ 3

16 6½ 316 6½ 3

16 6½ 716 7 — 7 —

5 6½ ¼ 6½ ¼ 7 — 6½ ½ 7 — 7 —

5116 6½ 5

16 6½ 516 7 — 7 1

16 7 116 7 1

16

518 6½ 3

8 6½ 38 7 — 7 1

8 7 18 7 1

8

5316 6½ 7

16 7 — 7 — 7 316 7 3

16 7 316

5¼ 6½ ½ 7 — 7 — 7 ¼ 7 ¼ 7½ —

5516 7 1

16 7 116 7 1

16 7 516 7 5

16 7½ —

538 7 1

8 7 18 7 1

8 7 38 7 3

8 7½ —

5716 7 3

16 7 316 7 3

16 7 716 7½ — 7½ —

5½ 7 ¼ 7 ¼ 7½ — 7 ½ 7½ — 7½ —

5916 7 5

16 7 516 7½ — 7½ 1

16 7½ 116 7½ 1

16

558 7 3

8 7 38 7½ — 7½ 1

8 7½ 18 7½ 1

8

51116 7 7

16 7½ — 7½ — 7½ 316 7½ 3

16 7½ 316







5¾ 7 18 7 1

8 7½ — 7 ¼ 7 ¼ 7½ —

51316 7 3

16 7 316 7½ — 7 5

16 7½ — 7½ —

578 7 ¼ 7 ¼ 7½ — 7 3

8 7½ — 7½ —

51516 7 5

16 7½ — 7½ — 7½ — 7½ — 7½ —

6 7 38 7½ — 7½ — 7½ — 7½ — 7½ —

6 116 7½ — 7½ — 7½ — 7½ 1

16 7½ 116 7½ 1

16

6 18 7½ — 7½ — 7½ — 7½ 1

8 7½ 18 8 —

6 316 7½ 1

16 7½ 116 7½ 1

16 7½ 316 7½ 3

16 8 —

6¼ 7½ 18 7½ 1

8 8 — 7½ ¼ 7½ ¼ 8 —

6 516 7½ 3

16 7½ 316 8 — 7½ 5

16 8 — 8 —

6 38 7½ ¼ 7½ ¼ 8 — 7½ 3

8 8 — 8 —

6716 7½ 5

16 8 — 8 — 8 — 8 — 8 —

6½ 7½ 38 8 — 8 — 8 — 8 — 8 —

6916 8 — 8 — 8 — 8 1

16 8 116 8 1

16

6 58 8 — 8 — 8 — 8 1

8 8 18

61116 8 1

16 8 116 8 1

16 8 316 8 3

16

6¾ 8 18 8 1

8 8 ¼ 8 ¼

61316 8 3

16 8 316 8 5

16

678 8 ¼ 8 ¼ 8 3

8

61516 8 5

16

7 8 38

Note: bolt lengths exceeding 8 inches are not generally available except by special order






no washers 1 washer 2 washers no washers 1 washer 2 washers

Grip L , in. t, in. L , in. t, in. L , in. t, in. L , in. t, in. L , in. t, in. L , in. t, in.

5¾ 7 ½ 7½ — 7½ — 7½ ¼ 7½ ¼ 8 —513

16 7½ 116 7½ 1

16 7½ 116 7½ 5

16 7½ 516 8 —

578 7½ 1

8 7½ 18 7½ 1

8 7½ 38 7½ 3

8 8 —

51516 7½ 3

16 7½ 316 7½ 3

16 7½ 716 8 — 8 —

6 7½ ¼ 7½ ¼ 8 — 7½ ½ 8 — 8 —6 1

16 7½ 516 7½ 5

16 8 — 8 116 8 1

16 8 116

6 18 7½ 3

8 7½ 38 8 — 8 1

8 8 18 8 1

8

6 316 7½ 7

16 8 — 8 — 8 316 8 3

16 8 316

6¼ 7½ ½ 8 — 8 — 8 ¼ 8 ¼6 5

16 8 116 8 1

16 8 116 8 5

16 8 516

6 38 8 1

8 8 18 8 1

8 8 38 8 3

8

6716 8 3

16 8 316 8 3

16 8 716

6½ 8 ¼ 8 ¼ 8 ½69

16 8 516 8 5

16

6 58 8 3

8 8 38

61116 8 7

16

6¾ 8 ½

Note: bolt lengths exceeding 8 inches are not generally available except by special order



bolt length hsb

Documents

calibrated wrench method

engineering journal

nominal length increment

minimum length increment

diameter astm a325

astm a490 bolts

outer ply thickness

table c2 conservative