Standard Bolt Torque Chart — SAE & Metric by Grade

What are the torque values by bolt size?

This page lists one calculated torque estimate per size: SAE Grade 2, 5 and 8 in ft-lb for coarse (UNC) bolts from 1/4" to 1-1/4", and metric Class 8.8, 10.9 and 12.9 in Nm for coarse-thread bolts from M5 to M24. For example, a 3/8" Grade 5 bolt calculates to 30.9 ft-lb and an M10 Class 8.8 bolt to 50.5 Nm. These are illustrative estimates, not manufacturer-approved installation specifications. Actual torque depends on lubricant, plating, material, and application, so use the specified torque for your actual joint.

What is the torque for a Grade 5 bolt?

Calculated SAE Grade 5 estimates for coarse (UNC) thread, in ft-lb: 1/4" 8.5, 5/16" 17.4, 3/8" 30.9, 7/16" 49.4, 1/2" 75.4, 9/16" 108.7, 5/8" 150.1, 3/4" 266.5. The table on this page continues to 1-1/4". The calculation assumes K = 0.20 and 75% of proof load. These are illustrative estimates, not manufacturer-approved installation specifications. Use the specified torque for your actual joint.

What is the torque for an M8 bolt?

For M8 × 1.25, this calculation gives 25.5 Nm (18.8 ft-lb) for Class 8.8, 36.5 Nm (26.9 ft-lb) for Class 10.9 and 42.6 Nm (31.4 ft-lb) for Class 12.9, assuming K = 0.20 and 75% of proof load. This is an illustrative estimate, not a manufacturer-approved installation specification. Use the specified torque for your actual joint.

What is the torque for an M10 bolt?

For M10 × 1.5, this calculation gives 50.5 Nm (37.2 ft-lb) for Class 8.8, 72.2 Nm (53.2 ft-lb) for Class 10.9 and 84.4 Nm (62.2 ft-lb) for Class 12.9, assuming K = 0.20 and 75% of proof load. This is an illustrative estimate, not a manufacturer-approved installation specification. Use the specified torque for your actual joint.

What is the torque for an M12 bolt?

For M12 × 1.75, this calculation gives 88 Nm (64.9 ft-lb) for Class 8.8, 125.9 Nm (92.9 ft-lb) for Class 10.9 and 147.1 Nm (108.5 ft-lb) for Class 12.9, assuming K = 0.20 and 75% of proof load. This is an illustrative estimate, not a manufacturer-approved installation specification. Use the specified torque for your actual joint.

What do Class 8.8, 10.9 and 12.9 mean?

They identify mechanical property classes, not universal torque settings. The calculation uses proof stresses of 580 MPa for 8.8 up to M16, 600 MPa above M16, 830 MPa for 10.9 and 970 MPa for 12.9. A higher property class supports a higher proof load, but does not by itself determine the correct assembly torque or make a bolt interchangeable.

Can I reduce these values for oil or anti-seize?

Not by a universal percentage. Oil, anti-seize, plating and thread-lockers have product- and joint-specific friction behavior. Use the manufacturer’s torque and specified assembly condition; the former blanket lubricated toggle has been removed.

Do these estimates apply to fine threads or aluminum?

No. These examples use coarse threads and assume a suitably matched steel nut and adequate engagement. Aluminum thread strength, fine-thread stress area, coatings, flange geometry and torque-to-yield procedures require their own engineering or manufacturer specification.

Torque tools

As an Amazon Associate WhatSizeBolt earns from qualifying purchases. Tool picks are general options, not a fit guarantee for your vehicle or fastener.

• 1/2-Inch Click Torque Wrench (10–150 ft-lb)For larger fasteners. Check its range includes the torque you need.EPAuto 1/2" Drive Click Torque Wrench, 10–150 ft-lb — view on Amazon
• 3/8-Inch Click Torque Wrench (10–80 ft-lb)Reads small fasteners more accurately than a big wrench.LEXIVON 3/8" Drive Click Torque Wrench, 10–80 ft-lb (LX-182) — view on Amazon
• Torque Angle GaugeFor torque-to-yield bolts whose spec adds an angle after the initial torque.OEMTOOLS 25424 1/2" Drive Torque Angle Gauge — view on Amazon