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M22 bolt size
32 mm wrench
across-flats spanner / socket size for M22
M22 bolt — heavy structural steel.
Full specification
| System | Metric coarse |
| Nominal diameter | 22 mm |
| Thread pitch | 2.5 mm |
| Wrench / spanner (across flats) | 32 mm |
| Tap drill | 19.5 mm |
| Clearance hole | 24 mm |
| Common grade / class | 8.8 |
| Typical torque | 550 Nm (406 ft·lb) |
| Closest other-system size | ~7/8 inch |
🔧 Torque unit converter
Pre-filled with the typical torque for M22 (8.8, dry). Edit any field to convert.
⚠️ Torque values here are general references for 8.8 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 M22
M22 is used in structural steel connections, often alongside M20 and M24.
Some standards give M22 a 34 mm head — measure across the flats to be sure.
Frequently asked questions
- What size wrench or spanner fits M22?
- M22 bolt uses a 32 mm wrench or spanner, measured across the flats of the hex head.
- What is the torque for M22?
- A typical tightening torque for M22 bolt in 8.8 on dry threads is about 550 Nm (406 ft·lb). Always confirm against the manufacturer spec for important joints.
- What thread pitch and tap drill does M22 use?
- M22 bolt has a thread pitch of 2.5 mm and uses a 19.5 mm tap drill, with a 24 mm clearance hole.