11.3 mm drill size
A 11.3 mm metric drill is 0.4449 in (11.300 mm). It is the form (roll) tap, 65% thread drill for M12x1.5.
- Decimal inch
- 0.4449
- Millimeters
- 11.300
- Nearest 1/64
- 7/16" (+0.0074)
- Type
- metric drill
Nearest equivalents in other systems
Speeds and feeds: in mild steel an HSS drill starts at about 770 RPM and 0.0101 in/rev (7.78 IPM); in 6061 aluminum about 2,150 RPM.
11.3 mm drill speeds and feeds by material
Jobber-length twist drill, D = 0.4449 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 | 2,150 | 600 | 5,150 | 0.0093 | 20.0 | 47.9 |
| Brass / free-machining | 150 | 1,290 | 400 | 3,430 | 0.0074 | 9.55 | 25.4 |
| Low-carbon steel (1018) | 90 | 770 | 300 | 2,580 | 0.0101 | 7.78 | 26.1 |
| Alloy steel (4140, annealed) | 70 | 600 | 250 | 2,150 | 0.0111 | 6.66 | 23.9 |
| Stainless 304 | 40 | 340 | 150 | 1,290 | 0.0075 | 2.55 | 9.67 |
| Gray cast iron | 80 | 690 | 250 | 2,150 | 0.0076 | 5.24 | 16.3 |
| Titanium 6Al-4V | 25 | 210 | 100 | 860 | 0.0047 | 0.99 | 4.04 |
| Plastics (acetal) | 300 | 2,580 | 500 | 4,290 | 0.0056 | 14.4 | 24.0 |
Metric: Vc (m/min) = SFM × 0.3048; feed (mm/rev) = in/rev × 25.4. In steel, 770 RPM × 0.257 mm/rev = 198 mm/min.
Worked example: 11.3 mm drill in 1018 steel
- HSS drill in low-carbon steel: 90 SFM.
- RPM = 3.82 × 90 ÷ 0.4449 ≈ 770 RPM.
- Feed for a 0.445 in drill in mild steel ≈ 0.0101 in/rev.
- IPM = 770 × 0.0101 = 7.78 IPM.
Peck cycle by hole depth
| Depth | Cycle | Peck | Note |
|---|---|---|---|
| 3×D = 1.335 in (33.9 mm) | G81 (no peck) | None | Up to 3×D a sharp drill clears chips on its own. |
| 5×D = 2.224 in (56.5 mm) | G73 chip-break | 1 × D | Chip-break pecks; full retract if chips pack (soft aluminum, stainless). |
| 8×D = 3.559 in (90.4 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 11.3 mm drill
- M12x1.5 — form (roll) tap, 65% thread
Nearest drills
- 11.2 mm: 0.4409 in / 11.200 mm (-0.0039 in)
- 11.4 mm: 0.4488 in / 11.400 mm (+0.0039 in)
- 7/16": 0.4375 in / 11.112 mm (-0.0074 in)
- 11.1 mm: 0.4370 in / 11.100 mm (-0.0079 in)
Common questions
- What is a 11.3 mm drill in decimal and mm?
- 0.4449 in, or 11.300 mm; nearest fractional drill: 7/16" (0.4375 in, -0.0074 in); nearest number / letter drill: Letter Z (0.4130 in, -0.0319 in).
- What RPM for a 11.3 mm drill in steel?
- In low-carbon steel (1018) an HSS 11.3 mm drill (0.4449 in) runs about 770 RPM at 90 SFM; a carbide drill about 2,580 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
- What feed for a 11.3 mm drill?
- About 0.0101 in/rev in mild steel, 0.0093 in/rev in aluminum and 0.0075 in/rev in 304 stainless. At 770 RPM that is 7.78 IPM in steel (IPM = RPM × IPR).
- What RPM for a 11.3 mm drill in aluminum?
- 2,150 RPM with HSS (250 SFM) or up to 5,150 RPM with carbide (600 SFM), feeding about 0.0093 in/rev.
- What tap uses a 11.3 mm drill?
- M12x1.5 (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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