Construction

Bolt Torque Specs

Typical dry-thread torque values for SAE and metric bolt grades.

Updated Apr 19, 2026 2 min read

Dry, clean threads. Lubricated threads reduce torque by ~25%. Always check manufacturer spec.

SAE grade 5 (medium carbon, heat-treated)

SizeThreadTorque (ft-lb)Torque (N·m)
1/4"20912
5/16"181824
3/8"163142
7/16"145068
1/2"1376103
9/16"12111150
5/8"11150203
3/4"10266360
7/8"9430583
1"8644873

SAE grade 8 (alloy steel)

SizeThreadTorque (ft-lb)Torque (N·m)
1/4"201216
5/16"182534
3/8"164460
7/16"147095
1/2"13107145
9/16"12157213
5/8"11215292
3/4"10380515
7/8"9606822
1"89091233

Metric class 8.8

SizePitchTorque (N·m)Torque (ft-lb)
M40.732
M50.864
M61.0107
M81.252518
M101.55037
M121.758764
M142.0139103
M162.0215159
M202.5422311
M243.0732540

Metric class 10.9

SizePitchTorque (N·m)Torque (ft-lb)
M40.743
M50.897
M61.01511
M81.253626
M101.57253
M121.7512693
M142.0200148
M162.0310229
M202.5607448
M243.01050775
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