ASME B18.2.1 Hex Bolt Dimensions

ASTM A194 Grade 7 Specifications

ASME B18.2.1 Hex Bolts

ASME B18.2.1 Hex Bolts

ASME B18.2.1 Hex Bolt Dimensions (Imperial)

Nominal Size or Basic product Diameter (Inches) Full-Size Body Diameter, E Width Across Flats, F Width Across Corners, G Head Height, H Radius of Fillet, R Thread Length for Bolt Lengths, LT
6 inches & Shorter Over 6 inches
Max. Min. Basic Max. Min. Max. Min. Basic Max. Min. Max. Min. Nom. Nom.
1/4"
0.2500
0.260 0.237 7/16" 0.438 0.425 0.505 0.484 11/64" 0.188 0.150 0.03 0.01 0.750 1.000
5/16"
0.3125
0.324 0.298 1/2" 0.500 0.484 0.577 0.552 7/32" 0.235 0.195 0.03 0.01 0.875 1.125
3/8"
0.3750
0.388 0.360 9/16" 0.562 0.544 0.650 0.620 1/4" 0.268 0.226 0.03 0.01 1.000 1.250
7/16"
0.4375
0.452 0.421 5/8" 0.625 0.603 0.722 0.687 19/64" 0.316 0.272 0.03 0.01 1.125 1.375
1/2"
0.5000
0.515 0.482 3/4" 0.750 0.725 0.866 0.826 11/32" 0.364 0.302 0.03 0.01 1.250 1.500
5/8"
0.6250
0.642 0.605 15/16" 0.938 0.906 1.083 1.033 27/64" 0.444 0.378 0.06 0.02 1.500 1.750
3/4"
0.7500
0.768 0.729 1-1/8" 1.125 1.088 1.299 1.240 1/2" 0.524 0.455 0.06 0.02 1.750 2.000
7/8"
0.8750
0.895 0.852 1-5/16" 1.312 1.269 1.516 1.447 37/64" 0.604 0.531 0.06 0.02 2.000 2.250
1"
1.0000
1.022 0.976 1-1/2" 1.500 1.450 1.732 1.653 43/64" 0.700 0.591 0.09 0.03 2.250 2.500
1-1/8"
1.1250
1.149 1.098 1-11/16" 1.688 1.631 1.949 1.859 3/4" 0.780 0.658 0.09 0.03 2.500 2.750
1-1/4"
1.2500
1.277 1.223 1-7/8" 1.875 1.812 2.165 2.066 27/32" 0.876 0.749 0.09 0.03 2.750 3.000
1-3/8"
1.3750
1.404 1.345 2-1/16" 2.062 1.994 2.382 2.273 29/32" 0.940 0.810 0.09 0.03 3.000 3.250
1-1/2"
1.5000
1.531 1.470 2-1/4" 2.250 2.175 2.598 2.480 1" 1.036 0.902 0.09 0.03 3.250 3.500
1-5/8"
1.6250
1.658 1.591 2-7/16" 2.438 2.356 2.815 2.616 1-3/32" 1.116 0.978 0.09 0.03 3.500 3.750
1-3/4"
1.7500
1.785 1.716 2-5/8" 2.625 2.538 3.031 2.893 1-5/32" 1.196 1.054 0.12 0.04 3.750 4.000
1-7/8"
1.8750
1.912 1.839 2-13/16" 2.812 2.719 3.248 3.099 1-1/4" 1.276 1.130 0.12 0.04 4.000 4.250
2"
2.0000
2.039 1.964 3" 3.000 2.9000 3.464 3.306 1-11/32" 1.388 1.175 0.12 0.04 4.250 4.500
2 1/4"
2.2500
2.305 2.214 3-3/8" 3.375 3.262 3.897 3.719 1-1/2" 1.548 1.327 0.19 0.06 4.750 5.000
2 1/2"
2.5000
2.559 2.461 3-3/4" 3.750 3.625 4.330 4.133 1-21/32" 1.708 1.479 0.19 0.06 5.250 5.500
2-3/4"
2.7500
2.827 2.711 4-1/8" 4.125 3.988 4.763 4.546 1-13/16" 1.869 1.632 0.19 0.06 5.750 6.000
3"
3.0000
3.081 2.961 4-1/2" 4.500 4.350 5.196 4.959 2" 2.060 1.815 0.19 0.06 6.250 6.500
3-1/4"
3.2500
3.335 3.210 4-7/8" 4.875 4.712 5.629 5.372 2-3/16" 2.251 1.936 0.19 0.06 6.750 7.000
3-1/2"
3.5000
3.589 3.461 5-1/4" 5.250 5.075 6.062 5.786 2-5/16" 2.380 2.057 0.19 0.06 7.250 7.500
3-3/4"
3.7500
3.858 3.726 5-5/8" 5.625 5.437 6.495 6.198 2-1/2" 2.572 2.241 0.19 0.06 7.750 8.000
4"
4.0000
4.111 3.975 6" 6.000 5.800 6.928 6.612 2-11/16" 2.764 2.424 0.19 0.06 8.250 8.500

ASTM A194 Grade 7 Fastener Coatings