What is a 1.6 mm drill in decimal and mm?

0.0630 in, or 1.600 mm; nearest fractional drill: 1/16" (0.0625 in, -0.0005 in); nearest number / letter drill: #52 (0.0635 in, +0.0005 in).

What RPM for a 1.6 mm drill in steel?

In low-carbon steel (1018) an HSS 1.6 mm drill (0.0630 in) runs about 5,460 RPM at 90 SFM; a carbide drill about 18,190 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.

What feed for a 1.6 mm drill?

About 0.0015 in/rev in mild steel, 0.0014 in/rev in aluminum and 0.0010 in/rev in 304 stainless. At 5,460 RPM that is 8.19 IPM in steel (IPM = RPM × IPR).

What RPM for a 1.6 mm drill in aluminum?

15,160 RPM with HSS (250 SFM) or up to 36,380 RPM with carbide (600 SFM), feeding about 0.0014 in/rev.

1.6 mm drill size

A 1.6 mm metric drill is 0.0630 in (1.600 mm). It is the cut tap, 75% thread drill for M2x0.4.

Decimal inch: 0.0630
Millimeters: 1.600
Nearest 1/64: 1/16" (+0.0005)
Type: metric drill

Nearest equivalents in other systems

Drills closest to 1.6 mm
System	Drill	Inch	mm	Difference
Fractional	1/16"	0.0625	1.588	-0.0005 in
Number / letter	#52	0.0635	1.613	+0.0005 in

Speeds and feeds: in mild steel an HSS drill starts at about 5,460 RPM and 0.0015 in/rev (8.19 IPM); in 6061 aluminum about 15,160 RPM.

1.6 mm drill speeds and feeds by material

Jobber-length twist drill, D = 0.0630 in. RPM = 3.82 × SFM ÷ D, rounded to 10. Feed per rev scales with diameter and material; IPM = RPM × IPR.

1.6 mm drilling speeds
Material	HSS SFM	HSS RPM	Carbide SFM	Carbide RPM	Feed (in/rev)	HSS IPM	Carbide IPM
Aluminum (6061)	250	15,160	600	36,380	0.0014	21.2	50.9
Brass / free-machining	150	9,100	400	24,260	0.0012	10.9	29.1
Low-carbon steel (1018)	90	5,460	300	18,190	0.0015	8.19	27.3
Alloy steel (4140, annealed)	70	4,240	250	15,160	0.0015	6.36	22.7
Stainless 304	40	2,430	150	9,100	0.0010	2.43	9.10
Gray cast iron	80	4,850	250	15,160	0.0009	4.37	13.6
Titanium 6Al-4V	25	1,520	100	6,060	0.0008	1.22	4.85
Plastics (acetal)	300	18,190	500	30,320	0.0025	45.5	75.8

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, 5,460 RPM × 0.038 mm/rev = 208 mm/min.

Worked example: 1.6 mm drill in 1018 steel

HSS drill in low-carbon steel: 90 SFM.
RPM = 3.82 × 90 ÷ 0.0630 ≈ 5,460 RPM.
Feed for a 0.063 in drill in mild steel ≈ 0.0015 in/rev.
IPM = 5,460 × 0.0015 = 8.19 IPM.

Peck cycle by hole depth

1.6 mm drill: depth and canned cycle
Depth	Cycle	Peck	Note
3×D = 0.189 in (4.8 mm)	G81 (no peck)	None	Up to 3×D a sharp drill clears chips on its own.
5×D = 0.315 in (8 mm)	G73 chip-break	1 × D	Chip-break pecks; full retract if chips pack (soft aluminum, stainless).
8×D = 0.504 in (12.8 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 1.6 mm drill

M2x0.4 — cut tap, 75% thread · tap speeds and feeds

Nearest drills

1/16": 0.0625 in / 1.588 mm (-0.0005 in)
#52: 0.0635 in / 1.613 mm (+0.0005 in)
1.55 mm: 0.0610 in / 1.550 mm (-0.0020 in)
1.65 mm: 0.0650 in / 1.650 mm (+0.0020 in)

Drill speed calculator, prefilled for 1.6 mm Drill finder: sizes near 1.6 mm Metric drill chart Decimal equivalent chart

Common questions

What is a 1.6 mm drill in decimal and mm?: 0.0630 in, or 1.600 mm; nearest fractional drill: 1/16" (0.0625 in, -0.0005 in); nearest number / letter drill: #52 (0.0635 in, +0.0005 in).
What RPM for a 1.6 mm drill in steel?: In low-carbon steel (1018) an HSS 1.6 mm drill (0.0630 in) runs about 5,460 RPM at 90 SFM; a carbide drill about 18,190 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
What feed for a 1.6 mm drill?: About 0.0015 in/rev in mild steel, 0.0014 in/rev in aluminum and 0.0010 in/rev in 304 stainless. At 5,460 RPM that is 8.19 IPM in steel (IPM = RPM × IPR).
What RPM for a 1.6 mm drill in aluminum?: 15,160 RPM with HSS (250 SFM) or up to 36,380 RPM with carbide (600 SFM), feeding about 0.0014 in/rev.
What tap uses a 1.6 mm drill?: M2x0.4 (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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