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Building Design and Construction Handbook - Merritt - Ventech!

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7.92 SECTION SEVEN<br />

7.30.1 ASD for Bolts<br />

Allowable tension <strong>and</strong> shear stresses for bolts are listed in Table 7.24. The allowable<br />

bearing load at a bolt hole is 1.5F udt, where F u is the specified tensile strength, d<br />

is the nominal bolt diameter, <strong>and</strong> t � thickness of connected part.<br />

Table 7.25 tabulates maximum sizes for st<strong>and</strong>ard, oversize, <strong>and</strong> slotted bolt<br />

holes. Oversize holes are permitted only in slip-critical connections. In slip-critical<br />

connections, slots may be formed without regard to the direction of loading; but in<br />

bearing-type connections, slot length should be placed normal to the direction of<br />

TABLE 7.24 Allowable Stresses, ksi, for Bolts <strong>and</strong> Threaded Parts a<br />

Fasteners<br />

St<strong>and</strong>ardsize<br />

holes<br />

b<br />

Shear in slip-critical connections Fv Oversize<br />

<strong>and</strong> shortslot<br />

holes<br />

Long-slot holes<br />

Transverse<br />

load c<br />

Parallel<br />

load c<br />

Shear<br />

F v<br />

Bearing-type connections<br />

Tension F t, including<br />

reduction for shear stress<br />

d<br />

ƒ v<br />

A407 bolts 10.0e,ƒ 26 � 1.8ƒv � 20<br />

0.17 h Fv 0.43Fv � 1.8ƒv � 0.33 h,i<br />

Threaded Parts <strong>and</strong><br />

A449 bolts,<br />

threaded g not<br />

excluded from shear<br />

planes<br />

Threaded parts <strong>and</strong><br />

A449 bolts, threads<br />

excluded from shear<br />

planes g<br />

A325 bolts, when<br />

threads are not<br />

excluded from shear<br />

planes<br />

A325 bolts, when<br />

threads are excluded<br />

from shear planes<br />

A490 bolts, when<br />

threads are not<br />

excluded from shear<br />

planes<br />

A490 bolts, when<br />

threads are excluded<br />

from shear planes<br />

F v<br />

0.22 h Fv 0.43 Fv � 1.4ƒv � 0.33 h Fv ƒ 2 2<br />

17.0 15.0 12.0 10.0 21.0 �(44) � 4.39ƒv ƒ 2 2<br />

17.0 15.0 12.0 10.0 30.0 �(44) � 2.15ƒv ƒ 2 2<br />

21.0 18.0 15.0 13.0 28.0 �(54) � 3.75ƒv ƒ 2 2<br />

21.0 18.0 15.0 13.0 40.0 �(54) � 1.82ƒv a For wind or seismic loading, acting alone or in combination with design dead <strong>and</strong> live loads, allowable stresses<br />

the table may be increased one-third, if the required section then is at least that required for design, dead, live, <strong>and</strong><br />

impact loads without this increase. For tension combined with shear, the coefficients of ƒ v in the tabulated formulas<br />

could not be changed.<br />

b Assumes clean mill scale <strong>and</strong> blast-cleaned surfaces with Class A coatings (slip coefficient 0.33). For special<br />

faying-surface conditions, see the Research Council on Structural Connections specification.<br />

c Relative to the long axis of the slotted hole.<br />

d Static loading only. For fatigue conditions, see the AISC ASD ‘‘Specification for Structural Steel for <strong>Building</strong>s.’’<br />

e Threads permitted in shear planes.<br />

ƒ Reduce 20% for bolts in bearing-type splices of tension members if the fastener pattern has a length, parallel to<br />

the line of force, exceeding 50 in.<br />

g Applicable to threaded parts meeting the requirements of ASTM A36, A242, A441, A529, A572, A588, A709,<br />

A852 <strong>and</strong> to A449 bolts in bearing-type connections requiring bolt diameters exceeding 1 1 ⁄2 in.<br />

h Fv � minimum tensile strength, ksi, of bolts.<br />

i For the threaded portion of an upset rod, AbF t should be larger than 0.60A sF y, where A b is the area at the major<br />

lead diameter, A s is the nominal body area before upsetting, <strong>and</strong> F v is the specified yield stress, ksi.

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