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M20 nut size
30 mm wrench
across-flats spanner / socket size for M20 nut
M20 nut — pairs with M20 bolts.
Full specification
| System | Metric |
| Nominal diameter | 20 mm thread |
| Thread pitch | 2.5 mm |
| Wrench / spanner (across flats) | 30 mm |
| Tap drill | n/a |
| Clearance hole | n/a |
| Common grade / class | matches bolt |
| Typical torque | 410 Nm (302 ft·lb) |
| Closest other-system size | ~3/4 in nut |
🔧 Torque unit converter
Pre-filled with the typical torque for M20 nut (matches bolt, dry). Edit any field to convert.
⚠️ Torque values here are general references for matches bolt 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 M20 nut
An M20 hex nut takes a 30 mm wrench across the flats.
Use a deep socket and breaker bar — M20 nuts are beyond hand-spanner torque.
Frequently asked questions
- What size wrench or spanner fits M20 nut?
- M20 nut uses a 30 mm wrench or spanner, measured across the flats of the hex head.
- What is the torque for M20 nut?
- A typical tightening torque for M20 nut in matches bolt on dry threads is about 410 Nm (302 ft·lb). Always confirm against the manufacturer spec for important joints.
- What thread pitch and tap drill does M20 nut use?
- M20 nut has a thread pitch of 2.5 mm and uses a n/a tap drill, with a n/a clearance hole.