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9/16-inch bolt size
13/16 in wrench
across-flats spanner / socket size for 9/16 in
9/16-inch bolt — heavy machinery and trucks.
Full specification
| System | Imperial UNC |
| Nominal diameter | 9/16 in (14.29 mm) |
| Thread pitch | 12 TPI |
| Wrench / spanner (across flats) | 13/16 in |
| Tap drill | 31/64 in |
| Clearance hole | 37/64 in |
| Common grade / class | Grade 5 |
| Typical torque | 149 Nm (110 ft·lb) |
| Closest other-system size | ~M14 |
🔧 Torque unit converter
Pre-filled with the typical torque for 9/16 in (Grade 5, dry). Edit any field to convert.
⚠️ Torque values here are general references for Grade 5 on clean, dry threads. Lubrication, coatings, and the joint material change the figure significantly. For structural, automotive, or safety-critical work, always use the torque specified by the manufacturer or engineer.
About 9/16 in
9/16-12 is used in heavier truck and machinery applications.
This size needs a 13/16 in wrench, often missing from basic sets.
Frequently asked questions
- What size wrench or spanner fits 9/16 in?
- 9/16-inch bolt uses a 13/16 in wrench or spanner, measured across the flats of the hex head.
- What is the torque for 9/16 in?
- A typical tightening torque for 9/16-inch bolt in Grade 5 on dry threads is about 149 Nm (110 ft·lb). Always confirm against the manufacturer spec for important joints.
- What thread pitch and tap drill does 9/16 in use?
- 9/16-inch bolt has a thread pitch of 12 TPI and uses a 31/64 in tap drill, with a 37/64 in clearance hole.