Page 266 - Structural Steel Designers Handbook AISC, AASHTO, AISI, ASTM, and ASCE-07 Design Standards

Brockenbrough_Ch05.qxd 9/29/05 5:12 PM Page 5.46

CRITERIA FOR BUILDING DESIGN

5.46 CHAPTER FIVE

TABLE 5.9 Minimum Bolt Pretension, kN*
Bolt size, mm A325M bolts A490M bolts
M16 91 114
M20 142 179
M22 176 221
M24 205 257
M27 267 334
M30 326 408
M36 475 595
*Equal to 0.70 of minimum tensile strength of bolts, rounded off
to nearest kN, as specified in ASTM specifications for A325M and
A490M bolts with UNC threads.
Source: “Specification for Structural Steel Buildings,” American
Institute of Steel Construction, Chicago, Ill., 2005, with permission.

When A490 or A490M bolts over 1 in (25 mm) in diameter are used in slotted or oversized holes
5
in external plies, a / 16-in-thick (8-mm) hardened washer (conforming to ASTM F436 except for
thickness) should be used in lieu of the standard washer.

5.9.6 Holes for Bolted Connections
Maximum nominal sizes of holes for bolts are given in either Tables 5.10 or 5.11, but larger holes are
permitted in column base details, such as required for location tolerance of anchor rods. Standard
holes or short-slotted holes transverse to the direction of the load should generally be used, unless
1
oversized holes or slotted holes are required and approved. Finger shims up to / 4 in (6 mm) thick
may be used in slip-critical connections without reducing the nominal shear strength of the fastener
to that specified for slotted holes.
Oversized holes are permitted in any or all plies of slip-critical connections, but must not be used
in bearing-type connections. Hardened washers should be installed over oversized holes in an outer
ply when high-strength bolts are used.
Short-slotted holes may be used in both slip-critical or bearing-type connections. Slots may be
used for any direction of loading in slip-critical connections, but should have their length normal to
the direction of the load in bearing-type connections. Washers should be installed over short-slotted
holes in an outer ply and, when high-strength bolts are used, hardened washers should be used.
Long-slotted holes may be used in only one of the connected parts of either a slip-critical or
bearing-type connection at an individual faying surface. Long-slotted holes may be used for any

TABLE 5.10 Nominal Hole Dimensions, in
Standard hole Oversized hole Short-slot Long-slot
Bolt diameter diameter diameter (width × length) (width × length)

1 9 5 9 11 9 1
/ 2 / 16 / 8 / 16 × / 16 / 16 × 1 / 4
5 11 13 11 7 11 9
/ 8 / 16 / 16 / 16 × / 8 / 16 × 1 / 16
3 13 15 13 / 16 × 1 13 7
/ 4 / 16 / 16 / 16 × 1 / 8
7 15 1 15 1 15 3
/ 8 / 16 1 / 16 / 16 × 1 / 8 / 16 × 2 / 16
5
1
1
1
1
1
1 1 / 16 1 / 4 1 / 16 × 1 / 16 1 / 16 × 2 / 2
3
1 1 5 (d + / 16) × (d + / 8) (d + / 16) × (2.5 × d)
1
≥1 / 8 d + / 16 d + / 16
Note: d is nominal bolt diameter, in.
Source: “Specification for Structural Steel Buildings,” American Institute of Steel Construction, Chicago, Ill., 2005,
with permission.
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