# 9/16 inch bolt torque

Tighten a 9/16-12 UNC grade 5 bolt to 109 ft-lb (147 N·m) with dry threads, or 82 ft-lb when lubricated. Grade 8 takes 154 ft-lb and grade 2 takes 70 ft-lb.

## 9/16 torque by thread series and SAE grade

| Thread | Grade | Dry torque (K 0.20) | Lubricated (K 0.15) | Clamp load |
|---|---|---|---|---|
| 9/16-12 UNC | Grade 2 | 70 ft-lb (95 N·m) | 53 ft-lb | 7,505 lbf |
| 9/16-12 UNC | Grade 5 | 109 ft-lb (147 N·m) | 82 ft-lb | 11,599 lbf |
| 9/16-12 UNC | Grade 8 | 154 ft-lb (208 N·m) | 115 ft-lb | 16,375 lbf |
| 9/16-18 UNF | Grade 2 | 78 ft-lb (106 N·m) | 59 ft-lb | 8,373 lbf |
| 9/16-18 UNF | Grade 5 | 121 ft-lb (164 N·m) | 91 ft-lb | 12,940 lbf |
| 9/16-18 UNF | Grade 8 | 171 ft-lb (232 N·m) | 128 ft-lb | 18,268 lbf |

Clamp load = 75 % of proof load. Method: T = K × F × d.

## 9/16 bolt data

- Threads: 9/16-12 UNC, 9/16-18 UNF
- Wrench: 13/16 in
- Tap drill: 31/64 (0.4844 in) for UNC, 33/64 (0.5156 in) for UNF

## Method

Proof strength from SAE J429 × tensile stress area As = 0.7854 × (D − 0.9743/n)² (ASME B1.1). F = 75 % of proof load. T = K × F × D with K = 0.20 dry, 0.15 lubricated.

## FAQ

**What is the torque for a 9/16 grade 5 bolt?**
About 109 ft-lb dry for 9/16-12 UNC and 121 ft-lb for 9/16-18 UNF, based on 75 % of proof load.

**What is the torque for a 9/16 grade 8 bolt?**
About 154 ft-lb dry for 9/16-12 UNC and 171 ft-lb for 9/16-18 UNF.

**What is the torque for a 9/16 grade 2 bolt?**
About 70 ft-lb dry for 9/16-12 UNC.

**What size wrench fits a 9/16 bolt?**
A standard 9/16" hex cap screw takes a 13/16" wrench or socket.

Source page: https://machinistcharts.com/bolt-torque/9-16-inch/
Updated: 2026-10-05
Publisher: MachinistCharts (https://machinistcharts.com)