6-32 tap drill size
Use a #36 drill (0.1065 in) for a 6-32 cutting tap at 75% thread.
| Tap type | Drill | Decimal (in) |
|---|---|---|
| Cutting tap, 75% thread | #36 | 0.1065 |
| Cutting tap, 50% thread (hard material) | #32 | 0.1160 |
| Roll / form tap, 65% thread | 1/8 | 0.1250 |
| Helicoil / STI insert (#6-32×1D) | #25 | 0.1495 |
- Pitch
- 0.7938 mm (32 TPI)
- Major Ø
- 0.1380
- Pitch Ø
- 0.1177
- Minor Ø
- 0.0997
6-32 tapping speeds and feeds
Feed = pitch (0.0313 in per rev). Starting points for a general-purpose HSS cut tap:
- Aluminum 6061 / 7075: 1,940 RPM · 60.6 IPM
- Free-machining / mild steel: 550 RPM · 17.2 IPM
- 304 / 316 stainless: 280 RPM · 8.75 IPM
6-32 tap speeds and feeds: all materials, form taps and G84 code · #36 drill size and speeds
Common questions
- What size drill for a 6-32 tap?
- Use a #36 drill (0.1065 in) for a 6-32 cutting tap at 75% thread.
- What drill for a 6-32 roll (form) tap?
- About 0.1242 in; the nearest standard drill is 1/8. Check your tap maker's table.
- What drill for a 6-32 Helicoil?
- Drill #25 (0.1495 in), then tap with the 6-32 STI tap.
Other UNC sizes
Drill sizes from Machinery's Handbook and ASME B1.1/B1.13M; roll tap sizes from the form-tap formula. Tap and insert makers' tables are authoritative.
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