Inconel 718 Heavy Hex Bolt to ASME B18.2.6 Heavy Hex Structral Bolts
ASME B18.2.6 Heavy Hex Structral Bolts Dimensions
| Nominal Size or Basic Product Diameter [Note (1)] |
Body Diameter, E [Note (2) and (3)] |
Width Across Flats, F [Note (4)] |
Width Across Corners, G |
Head Height, H [Note (5)] |
Radius of Fillet, R |
Thread Length, Lr [Note (6)] |
Transition Thread Length, Y [Note (6)] |
Maximum Total Runout of Bearing Surface FIM [Note (4)] |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Max. | Min. | Nom. | Max. | Min. | Max. | Min. | Nom. | Max. | Min. | Max. | Min. | Ref. | Ref. | |||
| ½ | 0.500 | 0.515 | 0.482 | ⅞ | 0.875 | 0.850 | 1.010 | 0.969 | ⁵⁄₁₆ | 0.323 | 0.302 | 0.031 | 0.009 | 1.00 | 0.19 | 0.016 |
| ⁵⁄₈ | 0.718 | 0.642 | 0.605 | 1⅙ | 1.062 | 1.031 | 1.227 | 1.175 | 25⁄64 | 0.403 | 0.378 | 0.062 | 0.021 | 1.25 | 0.22 | 0.019 |
| ¾ | 0.750 | 0.768 | 0.729 | 1¼ | 1.250 | 1.212 | 1.443 | 1.383 | 15⁄32 | 0.483 | 0.455 | 0.062 | 0.021 | 1.38 | 0.25 | 0.022 |
| ⅞ | 0.875 | 0.895 | 0.852 | 1 7⁄16 | 1.438 | 1.394 | 1.660 | 1.589 | 35⁄64 | 0.563 | 0.531 | 0.062 | 0.031 | 1.50 | 0.28 | 0.025 |
| 1 | 1.000 | 1.022 | 0.976 | 1 ⅝ | 1.718 | 1.575 | 1.876 | 1.796 | 39⁄64 | 0.627 | 0.591 | 0.093 | 0.062 | 1.75 | 0.31 | 0.028 |
| 1⅛ | 1.125 | 1.149 | 1.098 | 1 13⁄16 | 1.812 | 1.756 | 2.093 | 2.002 | 11⁄16 | 0.718 | 0.658 | 0.093 | 0.062 | 2.00 | 0.3 | 0.032 |
| 1¼ | 1.250 | 1.277 | 1.223 | 2 | 2.000 | 1.938 | 2.309 | 2.209 | 25⁄32 | 0.813 | 0.749 | 0.093 | 0.062 | 2.00 | 0.38 | 0.035 |
| 1⅜ | 1.375 | 1.404 | 1.345 | 2 3⁄16 | 2.188 | 2.119 | 2.526 | 2.416 | 27⁄32 | 0.878 | 0.810 | 0.093 | 0.062 | 2.25 | 0.44 | 0.038 |
| 1½ | 1.500 | 1.531 | 1.470 | 2 ⅜ | 2.375 | 2.300 | 2.742 | 2.622 | 15⁄16 | 0.974 | 0.902 | 0.093 | 0.062 | 2.25 | 0.44 | 0.041 |
GENERAL NOTE: See additional requirements in section 2.
NOTES:
(1) See para. 2.4.1.
(2) The body diameters are shown in this Table. Any swell or fin under the head or any die seam on the
body shall not exceed the basic bolt diameter by more than the following:
(a) 0.030 in. for sizes 1∕2 in.
(b) 0.050 in. for sizes 5∕8 in. and 3∕4 in.
(c) 0.060 in. for sizes over 3∕4 in. through 11∕4 in.
(d) 0.090 in. for sizes over 11∕4 in.
(3) See para. 2.1.9.4.
(4) See paras. 2.1.2 and 2.1.3.
(5) See paras. 2.1.1 and 2.1.4.
(6) See para. 2.1.9.2.
(7) See para. 2.1.6.
Length Tolerance. Bolt Length tolerance shall be as tabulated below.
| Nominal Bolt Length Tolerance [note(1)] | ||
|---|---|---|
| Nominal Bolt Size | Through 6 | Over 6 |
| ½ | -0.12 | -0.19 |
| ⅝ | -0.12 | -0.25 |
| ¾ through 1 | -0.19 | -0.25 |
| 1⅛ through 1½ | -0.25 | -0.25 |
Note: (1) There is no tolerance plus.
Threads. Threads shall be cut or rolled in accordance with ASME B1.1 Unified Coarse, Class 2A. Structural bolts shall not be undersized to accommodate heavy coatings. Threads that have been coated shall meet the requirements specified in ASTM F3125/F3125M.
Thread Acceptability. Unless otherwise specified by the purchaser, gaging for screw thread dimensional acceptability shall be in accordance with Gaging System 21, as specified in ASME B1.3.
Thread Length.
The length of thread on bolts shall be controlled by the grip gaging length, LG max., and the
body length, LB min.
Grip gaging length, LG, is the distance measured parallel to the axis of bolt from the underhead bearing
surface to the face of a noncounterbored or noncountersunk standard GO thread ring gage, assembled by hand
as far as the thread will permit. It shall be used as the criterion for inspection. The maximum grip
gaging length, as calculated and rounded to two decimal places for any bolt not threaded full length,
shall be equal to the nominal bolt length minus the thread length (LG max. = L nom. − LT). For bolts that
are threaded full length, LG max. defines the unthreaded length under the head and shall not exceed the
length of 2.5 times the thread pitch for sizes up to and including 1 in. diameter, and 3.5 times the
thread pitch for sizes larger than 1 in. diameter. LG max. represents the minimum design grip length of
the bolt and may be used for determining thread availability when selecting bolt lengths even though
usable threads extend beyond this point (see Table 2.1.9.2-1).
Thread length, LT, is a reference dimension, intended for calculation purposes only, that represents the
distance from the extreme end of the bolt to the last complete (full form) thread.
Body length, LB, is the distance measured parallel to the axis of the bolt from the underhead bearing
surface to the last scratch of thread, or to the top of the extrusion angle. It shall be used as a
criterion for inspection. The minimum body length, as calculated and rounded to two decimal places, shall
be equal to the maximum grip gaging length minus the transition thread length (LB min. = LG max. − Y).
Bolts of nominal lengths that have a calculated LB min. length equal to or shorter than 2.5 times the
thread pitch for sizes 1 in. diameter and smaller, and 3.5 times the thread pitch for sizes larger than 1
in. diameter, be threaded for full length (see Table 2.1.9.2-1).
Transition thread length, Y, is a reference dimension intended for calculation purposes only, that
represents the length of incomplete threads and tolerance on grip gaging length.
Incomplete Thread Diameter. The major diameter of incomplete thread shall not exceed the actual major diameter of the full form thread.
Fully Threaded Bolt Diameter. The diameter of any unthreaded portion of a bolt considered fully threaded shall be between the minimum pitch diameter and maximum major diameter of the threads.
Point. Point shall be chamfered or rounded at the manufacturer's option from approximately 0.016 in. below the minor diameter of the thread. The first full formed thread at major diameter is located a distance no greater than 2 times the pitch measured from the end of the bolt. This distance is to be determined by measuring how far the point enters into a cylindrical NOT GO major diameter ring gage (reference gage, see ASME B1.2).
Straightness.
Shanks of bolts shall be straight within the following limits at MMC:
(a) For bolts with nominal lengths to and including 12 in., the maximum camber shall be 0.006 in. per inch
(0.006L) of bolt length.
(b) For bolts with nominal lengths over 12 in. to and including 24 in., the maximum camber shall be 0.008
in. per inch (0.008L) of length.
A suggested gage and gaging procedure for checking bolt straightness is given in ASME B18.2.9.