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  4. ASME B18.2.1

ASME B18.2.1 Heavy Hex Bolts

HEAVY HEXAGON BOLT INCH THREAD

Nominal Size E F G H R LT
Body Dia Width Across Flats Width Across Corners Height Radius of Fillet Thread Length for Bolt Lengths
Max Min Max Min Max Min Max Min Max Min Nom Nom
3/8" 9.85 9.15 17.47 17 20.16 19.39 6.8 5.75 0.76 0.26 25.4 31.75
1/2" 13.08 12.25 22.22 21.59 25.65 24.62 9.24 7.68 31.75 38.1
5/8" 16.3 15.37 26.97 26.19 31.16 29.85 11.27 9.61 1.52 0.51 38.1 44.45
3/4" 19.5 18.52 31.75 30.79 36.65 35.13 13.3 11.56 44.45 50.8
7/8" 22.73 21.65 36.52 35.41 42.16 40.37 15.34 13.49 50.8 57.15
1" 25.95 24.79 41.27 40.01 47.65 45.62 17.78 15.02 2.28 0.77 57.15 63.5
1 1/8" 29.18 27.89 46.02 44.61 53.16 50.86 19.81 16.72 63.5 69.85
1 1/4" 32.43 31.07 50.8 49.23 58.64 56.11 22.25 19.03 69.85 76.2
1 3/8" 35.66 34.17 55.57 53.83 64.16 61.37 23.87 20.58 76.2 82.55
1 1/2" 38.88 37.34 60.32 58.42 69.64 66.6 26.31 22.92 82.55 88.9
1 5/8" 42.11 40.42 65.07 63.02 75.15 71.86 28.34 24.85 88.9 95.25
1 3/4" 45.33 43.59 69.85 67.62 80.64 77.09 30.37 26.78 3.04 1.02 95.25 101.6
1 7/8" 48.56 46.72 74.62 72.24 86.15 82.35 32.41 28.71 101.6 107.95
2" 51.79 49.89 79.37 76.84 91.64 87.61 35.25 29.85 107.95 114.3
2 1/4" 58.54 56.24 88.9 86.06 102.64 98.1 39.31 33.71 4.82 1.53 120.65 127
2 1/2" 64.99 62.51 98.42 95.25 113.63 108.59 43.38 37.57 133.35 139.7
2 3/4" 71.8 68.86 107.95 104.45 124.63 119.08 47.47 41.46 146.05 152.4
3" 78.25 75.21 117.47 113.67 135.63 129.6 52.32 46.11 158.75 165.1