What is a 2.9 mm drill in decimal and mm?

0.1142 in, or 2.900 mm; nearest fractional drill: 7/64" (0.1094 in, -0.0048 in); nearest number / letter drill: #33 (0.1130 in, -0.0012 in).

What RPM for a 2.9 mm drill in steel?

In low-carbon steel (1018) an HSS 2.9 mm drill (0.1142 in) runs about 3,010 RPM at 90 SFM; a carbide drill about 10,040 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.

What feed for a 2.9 mm drill?

About 0.0027 in/rev in mild steel, 0.0026 in/rev in aluminum and 0.0018 in/rev in 304 stainless. At 3,010 RPM that is 8.13 IPM in steel (IPM = RPM × IPR).

What RPM for a 2.9 mm drill in aluminum?

8,360 RPM with HSS (250 SFM) or up to 20,070 RPM with carbide (600 SFM), feeding about 0.0026 in/rev.

What tap uses a 2.9 mm drill?

M3.5x0.6 (cut tap, 75% thread).

2.9 mm drill size

A 2.9 mm metric drill is 0.1142 in (2.900 mm). It is the cut tap, 75% thread drill for M3.5x0.6.

Decimal inch: 0.1142
Millimeters: 2.900
Nearest 1/64: 7/64" (+0.0048)
Type: metric drill

Nearest equivalents in other systems

Drills closest to 2.9 mm
System	Drill	Inch	mm	Difference
Fractional	7/64"	0.1094	2.778	-0.0048 in
Number / letter	#33	0.1130	2.870	-0.0012 in

Speeds and feeds: in mild steel an HSS drill starts at about 3,010 RPM and 0.0027 in/rev (8.13 IPM); in 6061 aluminum about 8,360 RPM.

2.9 mm drill speeds and feeds by material

Jobber-length twist drill, D = 0.1142 in. RPM = 3.82 × SFM ÷ D, rounded to 10. Feed per rev scales with diameter and material; IPM = RPM × IPR.

2.9 mm drilling speeds
Material	HSS SFM	HSS RPM	Carbide SFM	Carbide RPM	Feed (in/rev)	HSS IPM	Carbide IPM
Aluminum (6061)	250	8,360	600	20,070	0.0026	21.7	52.2
Brass / free-machining	150	5,020	400	13,380	0.0022	11.0	29.4
Low-carbon steel (1018)	90	3,010	300	10,040	0.0027	8.13	27.1
Alloy steel (4140, annealed)	70	2,340	250	8,360	0.0027	6.32	22.6
Stainless 304	40	1,340	150	5,020	0.0018	2.41	9.04
Gray cast iron	80	2,680	250	8,360	0.0016	4.29	13.4
Titanium 6Al-4V	25	840	100	3,350	0.0014	1.18	4.69
Plastics (acetal)	300	10,040	500	16,730	0.0046	46.2	77.0

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, 3,010 RPM × 0.069 mm/rev = 206 mm/min.

Worked example: 2.9 mm drill in 1018 steel

HSS drill in low-carbon steel: 90 SFM.
RPM = 3.82 × 90 ÷ 0.1142 ≈ 3,010 RPM.
Feed for a 0.114 in drill in mild steel ≈ 0.0027 in/rev.
IPM = 3,010 × 0.0027 = 8.13 IPM.

Peck cycle by hole depth

2.9 mm drill: depth and canned cycle
Depth	Cycle	Peck	Note
3×D = 0.343 in (8.7 mm)	G81 (no peck)	None	Up to 3×D a sharp drill clears chips on its own.
5×D = 0.571 in (14.5 mm)	G73 chip-break	1 × D	Chip-break pecks; full retract if chips pack (soft aluminum, stainless).
8×D = 0.913 in (23.2 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 2.9 mm drill

M3.5x0.6 — cut tap, 75% thread · tap speeds and feeds

Nearest drills

#33: 0.1130 in / 2.870 mm (-0.0012 in)
#32: 0.1160 in / 2.946 mm (+0.0018 in)
2.85 mm: 0.1122 in / 2.850 mm (-0.0020 in)
2.95 mm: 0.1161 in / 2.950 mm (+0.0020 in)

Drill speed calculator, prefilled for 2.9 mm Drill finder: sizes near 2.9 mm Metric drill chart Decimal equivalent chart

Common questions

What is a 2.9 mm drill in decimal and mm?: 0.1142 in, or 2.900 mm; nearest fractional drill: 7/64" (0.1094 in, -0.0048 in); nearest number / letter drill: #33 (0.1130 in, -0.0012 in).
What RPM for a 2.9 mm drill in steel?: In low-carbon steel (1018) an HSS 2.9 mm drill (0.1142 in) runs about 3,010 RPM at 90 SFM; a carbide drill about 10,040 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
What feed for a 2.9 mm drill?: About 0.0027 in/rev in mild steel, 0.0026 in/rev in aluminum and 0.0018 in/rev in 304 stainless. At 3,010 RPM that is 8.13 IPM in steel (IPM = RPM × IPR).
What RPM for a 2.9 mm drill in aluminum?: 8,360 RPM with HSS (250 SFM) or up to 20,070 RPM with carbide (600 SFM), feeding about 0.0026 in/rev.
What tap uses a 2.9 mm drill?: M3.5x0.6 (cut tap, 75% 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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