3/32" drill size
A 3/32" fractional drill is 0.0938 in (2.381 mm).
- Decimal inch
- 0.0938
- Millimeters
- 2.381
- Nearest 1/64
- 3/32" (+0.0000)
- Type
- fractional drill
Nearest equivalents in other systems
| System | Drill | Inch | mm | Difference |
|---|---|---|---|---|
| Number / letter | #42 | 0.0935 | 2.375 | -0.0003 in |
| Metric | 2.4 mm | 0.0945 | 2.400 | +0.0007 in |
Speeds and feeds: in mild steel an HSS drill starts at about 3,670 RPM and 0.0022 in/rev (8.07 IPM); in 6061 aluminum about 10,190 RPM.
3/32" drill speeds and feeds by material
Jobber-length twist drill, D = 0.0938 in. RPM = 3.82 × SFM ÷ D, rounded to 10. Feed per rev scales with diameter and material; IPM = RPM × IPR.
| Material | HSS SFM | HSS RPM | Carbide SFM | Carbide RPM | Feed (in/rev) | HSS IPM | Carbide IPM |
|---|---|---|---|---|---|---|---|
| Aluminum (6061) | 250 | 10,190 | 600 | 24,450 | 0.0021 | 21.4 | 51.4 |
| Brass / free-machining | 150 | 6,110 | 400 | 16,300 | 0.0018 | 11.0 | 29.3 |
| Low-carbon steel (1018) | 90 | 3,670 | 300 | 12,220 | 0.0022 | 8.07 | 26.9 |
| Alloy steel (4140, annealed) | 70 | 2,850 | 250 | 10,190 | 0.0022 | 6.27 | 22.4 |
| Stainless 304 | 40 | 1,630 | 150 | 6,110 | 0.0015 | 2.44 | 9.17 |
| Gray cast iron | 80 | 3,260 | 250 | 10,190 | 0.0014 | 4.56 | 14.3 |
| Titanium 6Al-4V | 25 | 1,020 | 100 | 4,070 | 0.0012 | 1.22 | 4.88 |
| Plastics (acetal) | 300 | 12,220 | 500 | 20,370 | 0.0038 | 46.4 | 77.4 |
Small drills: the computed RPM is above most spindles. Run at your spindle's maximum and keep the feed per rev; feed drops in proportion.
Metric: Vc (m/min) = SFM × 0.3048; feed (mm/rev) = in/rev × 25.4. In steel, 3,670 RPM × 0.056 mm/rev = 205 mm/min.
Worked example: 3/32" drill in 1018 steel
- HSS drill in low-carbon steel: 90 SFM.
- RPM = 3.82 × 90 ÷ 0.0938 ≈ 3,670 RPM.
- Feed for a 0.094 in drill in mild steel ≈ 0.0022 in/rev.
- IPM = 3,670 × 0.0022 = 8.07 IPM.
Peck cycle by hole depth
| Depth | Cycle | Peck | Note |
|---|---|---|---|
| 3×D = 0.281 in (7.1 mm) | G81 (no peck) | None | Up to 3×D a sharp drill clears chips on its own. |
| 5×D = 0.469 in (11.9 mm) | G73 chip-break | 1 × D | Chip-break pecks; full retract if chips pack (soft aluminum, stainless). |
| 8×D = 0.750 in (19 mm) | G83 full retract | 0.5-1 × D, shrinking with depth | Retract to clear chips; reduce feed ~10-20% past 5×D. |
Taps that use a 3/32" drill
No standard UNC, UNF or metric tap in our tables calls for a 3/32" drill. Use it for clearance, pilot or reamer prep holes.
Nearest drills
- #42: 0.0935 in / 2.375 mm (-0.0003 in)
- 2.4 mm: 0.0945 in / 2.400 mm (+0.0007 in)
- 2.35 mm: 0.0925 in / 2.350 mm (-0.0012 in)
- #41: 0.0960 in / 2.438 mm (+0.0022 in)
Common questions
- What is a 3/32" drill in decimal and mm?
- 0.0938 in, or 2.381 mm; nearest number / letter drill: #42 (0.0935 in, -0.0003 in); nearest metric drill: 2.4 mm (0.0945 in, +0.0007 in).
- What RPM for a 3/32" drill in steel?
- In low-carbon steel (1018) an HSS 3/32" drill (0.0938 in) runs about 3,670 RPM at 90 SFM; a carbide drill about 12,220 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
- What feed for a 3/32" drill?
- About 0.0022 in/rev in mild steel, 0.0021 in/rev in aluminum and 0.0015 in/rev in 304 stainless. At 3,670 RPM that is 8.07 IPM in steel (IPM = RPM × IPR).
- What RPM for a 3/32" drill in aluminum?
- 10,190 RPM with HSS (250 SFM) or up to 24,450 RPM with carbide (600 SFM), feeding about 0.0021 in/rev.
- What size is a 3/32" drill?
- 0.0938 in / 2.381 mm. The nearest other drills are #42 (0.0935 in), 2.4 mm (0.0945 in), 2.35 mm (0.0925 in).
Nearby drill sizes
Sources
- Machinery's Handbook, 31st ed., Speeds and Feeds for Drilling, Reaming and Threading (Tables 17-23) — HSS and carbide drilling SFM (rounded).
- RedLine Tools (Productivity Inc.) catalog p. 340, Cobalt & HSS Drills Speeds & Feeds — feed per rev by drill diameter and material (middle of the catalog range).
- ASME B94.11M twist drills: number (#1-#80) and letter (A-Z) drill sizes; drill size reference.
Material feed multipliers (aluminum 1.3×, brass 1.1×, 4140 0.85×, stainless and titanium 0.7× the mild-steel feed) are JobLine estimates. Peck guidance is JobLine shop practice. Use your drill maker's data first.
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