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#8-32 bolt size
11/32 in wrench
across-flats spanner / socket size for #8-32
#8-32 bolt — small machine and electronics screw.
Full specification
| System | Imperial UNC |
| Nominal diameter | 0.164 in (4.2 mm) |
| Thread pitch | 32 TPI |
| Wrench / spanner (across flats) | 11/32 in |
| Tap drill | #29 (3.5 mm) |
| Clearance hole | #18 (4.6 mm) |
| Common grade / class | Grade 2 |
| Typical torque | 2.4 Nm (1.8 ft·lb) |
| Closest other-system size | ~M4 |
🔧 Torque unit converter
Pre-filled with the typical torque for #8-32 (Grade 2, dry). Edit any field to convert.
⚠️ Torque values here are general references for Grade 2 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 #8-32
#8-32 is a very common small American machine screw size.
A #29 drill is the standard tap drill for #8-32 threads.
Frequently asked questions
- What size wrench or spanner fits #8-32?
- #8-32 bolt uses a 11/32 in wrench or spanner, measured across the flats of the hex head.
- What is the torque for #8-32?
- A typical tightening torque for #8-32 bolt in Grade 2 on dry threads is about 2.4 Nm (1.8 ft·lb). Always confirm against the manufacturer spec for important joints.
- What thread pitch and tap drill does #8-32 use?
- #8-32 bolt has a thread pitch of 32 TPI and uses a #29 (3.5 mm) tap drill, with a #18 (4.6 mm) clearance hole.