Related Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
High-strength bolts with larger heads for structural and load-bearing connections
ASME B18.2.1 Heavy Hex Bolts Dimension Standard define larger head geometry and higher strength properties for demanding applications.

| Nominal Size or Basic Product Diameter | Full-Size Body Diameter, E | Width Across Flats, F | Width Across Corners, G | Head Height, H | Radius of Fillet, R | Nominal Thread Length, LT | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Max. | Min. | Basic | Max. | Min. | Max. | Min. | Basic | Max. | Min. | Max. | Min. | 152.4mm and Shorter | Over 152.4mm | ||
| 3/8 | 9.525 | 9.855 | 9.144 | 17.463 | 17.475 | 16.993 | 20.168 | 19.380 | 6.350 | 6.807 | 5.740 | 0.762 | 0.254 | 25.400 | 31.750 |
| 1/2 | 12.700 | 13.081 | 12.243 | 22.225 | 22.225 | 21.590 | 25.654 | 24.613 | 8.731 | 9.246 | 7.671 | 0.762 | 0.254 | 31.750 | 38.100 |
| 5/8 | 15.875 | 16.307 | 15.367 | 26.988 | 26.975 | 26.187 | 31.166 | 29.845 | 10.716 | 11.278 | 9.601 | 1.524 | 0.508 | 38.100 | 44.450 |
| 3/4 | 19.050 | 19.507 | 18.517 | 31.750 | 31.750 | 30.785 | 36.652 | 35.128 | 12.700 | 13.310 | 11.557 | 1.524 | 0.508 | 44.450 | 50.800 |
| 7/8 | 22.225 | 22.733 | 21.641 | 36.513 | 36.525 | 35.408 | 42.164 | 40.361 | 14.684 | 15.342 | 13.487 | 1.524 | 0.508 | 50.800 | 57.150 |
| 1 | 25.400 | 25.959 | 24.790 | 41.275 | 41.275 | 40.005 | 47.650 | 45.618 | 17.066 | 17.780 | 15.011 | 2.286 | 0.762 | 57.150 | 63.500 |
| 1 1/8 | 28.575 | 29.185 | 27.889 | 46.038 | 46.025 | 44.602 | 53.162 | 50.851 | 19.050 | 19.812 | 16.713 | 2.286 | 0.762 | 63.500 | 69.850 |
| 1 1/4 | 31.750 | 32.436 | 31.064 | 50.800 | 50.800 | 49.225 | 58.649 | 56.109 | 21.431 | 22.250 | 19.025 | 2.286 | 0.762 | 69.850 | 76.200 |
| 1 3/8 | 34.925 | 35.662 | 34.163 | 55.563 | 55.575 | 53.823 | 64.160 | 61.366 | 23.019 | 23.876 | 20.574 | 2.286 | 0.762 | 76.200 | 82.550 |
| 1 1/2 | 38.100 | 38.887 | 37.338 | 60.325 | 60.325 | 58.420 | 69.647 | 66.599 | 25.400 | 26.314 | 22.911 | 2.286 | 0.762 | 82.550 | 88.900 |
| 1 5/8 | 41.275 | 42.113 | 40.411 | 65.088 | 65.075 | 63.017 | 75.159 | 71.857 | 27.781 | 28.346 | 24.841 | 2.286 | 0.762 | 88.900 | 95.250 |
| 1 3/4 | 44.450 | 45.339 | 43.586 | 69.850 | 69.850 | 67.615 | 80.645 | 77.089 | 29.369 | 30.378 | 26.772 | 3.048 | 1.016 | 95.250 | 101.600 |
| 1 7/8 | 47.625 | 48.565 | 46.711 | 74.613 | 74.625 | 72.238 | 86.157 | 82.347 | 31.750 | 32.410 | 28.702 | 3.048 | 1.016 | 101.600 | 107.950 |
| 2 | 50.800 | 51.791 | 49.886 | 79.375 | 79.375 | 76.835 | 91.643 | 87.605 | 34.131 | 35.255 | 29.845 | 3.048 | 1.016 | 107.950 | 114.300 |
| 2 1/4 | 57.150 | 58.547 | 56.236 | 88.900 | 88.900 | 86.055 | 102.641 | 98.095 | 38.100 | 39.319 | 33.706 | 4.826 | 1.524 | 120.650 | 127.000 |
| 2 1/2 | 63.500 | 64.999 | 62.509 | 98.425 | 98.425 | 95.250 | 113.640 | 108.585 | 42.069 | 43.383 | 37.567 | 4.826 | 1.524 | 133.350 | 139.700 |
| 2 3/4 | 69.850 | 71.806 | 68.859 | 107.950 | 107.950 | 104.445 | 124.638 | 119.075 | 46.038 | 47.473 | 41.453 | 4.826 | 1.524 | 146.050 | 152.400 |
| 3 | 76.200 | 78.257 | 75.209 | 117.475 | 117.475 | 113.665 | 135.636 | 129.591 | 50.800 | 52.324 | 46.101 | 4.826 | 1.524 | 158.750 | 165.100 |
| Nominal Length | Nominal Size (inches) | |||||
|---|---|---|---|---|---|---|
| 1/4 to 3/8 | 7/16 and 1/2 | 9/16 to 3/4 | 7/8 and 1 | 1 1/8 to 1 1/2 | Over 1 1/2 | |
| Up to 25.4 mm, incl. | +0.508 0.762 |
+0.508 0.762 |
+0.508 0.762 |
... | ... | ... |
| Over 25.4 mm to 63.5 mm, incl. | +0.508 1.016 |
+1.016 1.524 |
+1.524 2.032 |
+2.032 2.54 |
+3.048 3.048 |
+4.572 4.572 |
| Over 63.5 mm to 101.6 mm, incl. | +1.016 1.524 |
+1.524 2.032 |
+2.032 2.54 |
+2.54 3.556 |
+4.064 4.064 |
+5.08 5.08 |
| Over 101.6 mm to 152.4 mm, incl. | +1.524 2.54 |
+2.032 2.54 |
+2.54 2.54 |
+3.048 4.064 |
+4.572 4.572 |
+5.588 5.588 |
| Longer than 152.4 mm | +2.54 4.572 |
+3.048 4.572 |
+3.556 4.572 |
+4.064 5.08 |
+5.588 5.588 |
+6.096 6.096 |