2.3 mm drill size
A 2.3 mm metric drill is 0.0906 in (2.300 mm). It is the form (roll) tap, 65% thread drill for M2.5x0.45.
- Decimal inch
- 0.0906
- Millimeters
- 2.300
- Nearest 1/64
- 3/32" (-0.0032)
- Type
- metric drill
Nearest equivalents in other systems
Speeds and feeds: in mild steel an HSS drill starts at about 3,800 RPM and 0.0021 in/rev (7.98 IPM); in 6061 aluminum about 10,550 RPM.
2.3 mm drill speeds and feeds by material
Jobber-length twist drill, D = 0.0906 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 | 10,550 | 600 | 25,310 | 0.0021 | 22.1 | 53.1 |
| Brass / free-machining | 150 | 6,330 | 400 | 16,870 | 0.0017 | 10.8 | 28.7 |
| Low-carbon steel (1018) | 90 | 3,800 | 300 | 12,660 | 0.0021 | 7.98 | 26.6 |
| Alloy steel (4140, annealed) | 70 | 2,950 | 250 | 10,550 | 0.0021 | 6.19 | 22.1 |
| Stainless 304 | 40 | 1,690 | 150 | 6,330 | 0.0014 | 2.37 | 8.86 |
| Gray cast iron | 80 | 3,370 | 250 | 10,550 | 0.0013 | 4.38 | 13.7 |
| Titanium 6Al-4V | 25 | 1,050 | 100 | 4,220 | 0.0011 | 1.16 | 4.64 |
| Plastics (acetal) | 300 | 12,660 | 500 | 21,090 | 0.0036 | 45.6 | 75.9 |
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, 3,800 RPM × 0.053 mm/rev = 203 mm/min.
Worked example: 2.3 mm drill in 1018 steel
- HSS drill in low-carbon steel: 90 SFM.
- RPM = 3.82 × 90 ÷ 0.0906 ≈ 3,800 RPM.
- Feed for a 0.091 in drill in mild steel ≈ 0.0021 in/rev.
- IPM = 3,800 × 0.0021 = 7.98 IPM.
Peck cycle by hole depth
| Depth | Cycle | Peck | Note |
|---|---|---|---|
| 3×D = 0.272 in (6.9 mm) | G81 (no peck) | None | Up to 3×D a sharp drill clears chips on its own. |
| 5×D = 0.453 in (11.5 mm) | G73 chip-break | 1 × D | Chip-break pecks; full retract if chips pack (soft aluminum, stainless). |
| 8×D = 0.724 in (18.4 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 2.3 mm drill
- M2.5x0.45 — form (roll) tap, 65% thread · tap speeds and feeds
Nearest drills
- #43: 0.0890 in / 2.261 mm (-0.0015 in)
- 2.25 mm: 0.0886 in / 2.250 mm (-0.0020 in)
- 2.35 mm: 0.0925 in / 2.350 mm (+0.0020 in)
- #42: 0.0935 in / 2.375 mm (+0.0029 in)
Common questions
- What is a 2.3 mm drill in decimal and mm?
- 0.0906 in, or 2.300 mm; nearest fractional drill: 3/32" (0.0938 in, +0.0032 in); nearest number / letter drill: #43 (0.0890 in, -0.0015 in).
- What RPM for a 2.3 mm drill in steel?
- In low-carbon steel (1018) an HSS 2.3 mm drill (0.0906 in) runs about 3,800 RPM at 90 SFM; a carbide drill about 12,660 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
- What feed for a 2.3 mm drill?
- About 0.0021 in/rev in mild steel, 0.0021 in/rev in aluminum and 0.0014 in/rev in 304 stainless. At 3,800 RPM that is 7.98 IPM in steel (IPM = RPM × IPR).
- What RPM for a 2.3 mm drill in aluminum?
- 10,550 RPM with HSS (250 SFM) or up to 25,310 RPM with carbide (600 SFM), feeding about 0.0021 in/rev.
- What tap uses a 2.3 mm drill?
- M2.5x0.45 (form (roll) tap, 65% thread).
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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