BOLT TORQUE SPECIFICATIONS

Grade 1 or 2
Grade 5
Grade 8
Special Alloy
Capscrew
Diameter (inch)
and minimum
tensile Strength (P.S.I.)
to 1/2" - 69,000
to 3/4" - 64,000
to 3/4" - 120,000
to 1" - 115,000
to 1" - 150,000 to 1" - 185,000
Bolt Size & Thread Pitch

Torque (foot/lbs) for plated bolts with clean, dry threads

1/4-20 6 10 12 14
-28 7 12 15 17
5/16-18 13 20 24 29
-24 14 22 27 35
3/8-16 23 36 44 58
-24 26 40 48 69
7/16-14 37 52 63 98
-20 41 57 70 110
1/2-13 57 80 98 145
-20 64 90 110 160
9/16-12 82 120 145 200
-18 91 135 165 220
5/8-11 111 165 210 280
-18 128 200 245 310
3/4-10 200 285 335 490
-16 223 317 370 530
7/8-9 315 430 500 760
-14 340 470 550 800
1-8 400 650 760 1130
-14 460 710 835 1210
Torque values shown are for high nickel-chrome Bowmalloy cap screws.  Other high-alloy cap screws may not have the same values.  Always use the manufacturer's specifications if they do not agree with this chart.
A Bolt must be torqued  properly before it's optimum strength can be realized.  Torqueing also maximizes the elasticity of the bolt to keep the fastener from loosening up on it's own.  Over torqueing can ruin this elastic effect.  When using lubricated threads, reduce torque values by the following amounts...45% when using anti-seize compound, 40% when using grease or heavy oil, 30% with graphite and 25% with white lead.  Increase torque values by 5% for unplated bolts.  Always use manufacturers torque specifications if they do not agree with this chart.