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A typical drawing for the heavy hex bolt manufactured in accordance with ASME B18.2.1
Heavy hex bolt manufactured in accordance with ASME B18.2.1 has a larger hex head than that of a standard hex bolt. The body diameter and head height of a heavy hex bolt are the same as that of a standard hex bolt. Two dimensional differences distinguish a heavy hex bolt from a standard hex bolt of the same nominal size are associated with the width of the head: the width across flats, F of the former is 1/8″ lager than the latter; the width across corners, G of the former is 0.144″ larger than the later. The weight of a heavy hex bolt can be calculated using the following equation: Weightheavy = ρ × [3 × 31/2 ÷ 8 × G2 + πE2L/4], ρ is the density of bolt material.
Nominal Size | E | H | |||
Max. | Min. | Basic | Max. | Min. | |
3/8 | 0.388 | 0.360 | 1/4 | 0.268 | 0.226 |
1/2 | 0.515 | 0.482 | 11/32 | 0.364 | 0.302 |
5/8 | 0.642 | 0.605 | 27/64 | 0.444 | 0.378 |
3/4 | 0.768 | 0.729 | 1/2 | 0.524 | 0.455 |
7/8 | 0.895 | 0.852 | 37/64 | 0.604 | 0.531 |
1 | 1.022 | 0.976 | 43/64 | 0.700 | 0.591 |
1-1/8 | 1.149 | 1.098 | 3/4 | 0.780 | 0.658 |
1-1/4 | 1.277 | 1.223 | 27/32 | 0.876 | 0.749 |
1-3/8 | 1.404 | 1.345 | 29/32 | 0.940 | 0.810 |
1-1/2 | 1.531 | 1.470 | 1 | 1.036 | 0.902 |
1-5/8 | 1.658 | 1.591 | 1-3/32 | 1.116 | 0.978 |
1-3/4 | 1.785 | 1.716 | 1-5/32 | 1.196 | 1.054 |
1-7/8 | 1.912 | 1.839 | 1-1/4 | 1.276 | 1.130 |
2 | 2.039 | 1.964 | 1-11/32 | 1.388 | 1.175 |
2-1/4 | 2.305 | 2.214 | 1-1/2 | 1.548 | 1.327 |
2-1/2 | 2.559 | 2.461 | 1-21/32 | 1.708 | 1.479 |
2-3/4 | 2.827 | 2.711 | 1-13/16 | 1.869 | 1.632 |
3 | 3.081 | 2.961 | 2 | 2.060 | 1.815 |
Nominal Size | F | G | ||
Max. | Min. | Max. | Min. | |
3/8 | 0.688 | 0.669 | 0.794 | 0.763 |
1/2 | 0.875 | 0.850 | 1.010 | 0.969 |
5/8 | 1.062 | 1.031 | 1.227 | 1.175 |
3/4 | 1.250 | 1.212 | 1.443 | 1.383 |
7/8 | 1.438 | 1.394 | 1.660 | 1.589 |
1 | 1.625 | 1.575 | 1.876 | 1.796 |
1-1/8 | 1.812 | 1.756 | 2.093 | 2.002 |
1-1/4 | 2.000 | 1.938 | 2.309 | 2.209 |
1-3/8 | 2.188 | 2.119 | 2.526 | 2.416 |
1-1/2 | 2.375 | 2.300 | 2.742 | 2.622 |
1-5/8 | 2.562 | 2.481 | 2.959 | 2.829 |
1-3/4 | 2.750 | 2.662 | 3.175 | 3.035 |
1-7/8 | 2.938 | 2.844 | 3.392 | 3.242 |
2 | 3.125 | 3.025 | 3.608 | 3.449 |
2-1/4 | 3.500 | 3.388 | 4.041 | 3.862 |
2-1/2 | 3.875 | 3.750 | 4.474 | 4.275 |
2-3/4 | 4.250 | 4.112 | 4.907 | 4.688 |
3 | 4.625 | 4.475 | 5.340 | 5.102 |
Nominal Size | R | LT | ||
Max. | Min. | L ≤ 6" | L > 6" | |
3/8 | 0.03 | 0.01 | 1.000 | 1.250 |
1/2 | 0.03 | 0.01 | 1.250 | 1.500 |
5/8 | 0.06 | 0.02 | 1.500 | 1.750 |
3/4 | 0.06 | 0.02 | 1.750 | 2.000 |
7/8 | 0.06 | 0.02 | 2.000 | 2.250 |
1 | 0.09 | 0.03 | 2.250 | 2.500 |
1-1/8 | 0.09 | 0.03 | 2.500 | 2.750 |
1-1/4 | 0.09 | 0.03 | 2.750 | 3.000 |
1-3/8 | 0.09 | 0.03 | 3.000 | 3.250 |
1-1/2 | 0.09 | 0.03 | 3.250 | 3.500 |
1-5/8 | 0.09 | 0.03 | 3.500 | 3.750 |
1-3/4 | 0.12 | 0.04 | 3.750 | 4.000 |
1-7/8 | 0.12 | 0.04 | 4.000 | 4.250 |
2 | 0.12 | 0.04 | 4.250 | 4.500 |
2-1/4 | 0.19 | 0.06 | 4.750 | 5.000 |
2-1/2 | 0.19 | 0.06 | 5.250 | 5.500 |
2-3/4 | 0.19 | 0.06 | 5.750 | 6.000 |
3 | 0.19 | 0.06 | 6.250 | 6.500 |
For L ≤ 6″, LT equals twice the basic thread diameter plus 0.25″; For L > 6″, LT equals twice the basic thread diameter plus 0.50″. For bolts that are threaded full length, LG defines the unthreaded length under the head, and LG ≤ 2.5 × P for sizes ≤ 1″ while LG ≤ 3.5 × P for sizes > 1″ (P = thread pitch). If bolt size ≤ 1″ and L ≤ LT + 2.5 × P, or, if bolt size > 1″ and L ≤ LT + 3.5 × P, the bolt shall be threaded for full length.
ASME B18.2.1 Nine Types of Bolts & Screws | ||
---|---|---|
Square Head Bolt | Hex Bolt | Heavy Hex Bolt |
Askew Head Bolt | Hex Cap Screw | Heavy Hex Screw |
Hex Flange Screw | Lobed Head Screw | Lag Screw |