What is a #52 drill in decimal and mm?

0.0635 in, or 1.613 mm; nearest fractional drill: 1/16" (0.0625 in, -0.0010 in); nearest metric drill: 1.6 mm (0.0630 in, -0.0005 in).

What RPM for a #52 drill in steel?

In low-carbon steel (1018) an HSS #52 drill (0.0635 in) runs about 5,410 RPM at 90 SFM; a carbide drill about 18,050 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.

What feed for a #52 drill?

About 0.0015 in/rev in mild steel, 0.0014 in/rev in aluminum and 0.0010 in/rev in 304 stainless. At 5,410 RPM that is 8.12 IPM in steel (IPM = RPM × IPR).

What RPM for a #52 drill in aluminum?

15,040 RPM with HSS (250 SFM) or up to 36,090 RPM with carbide (600 SFM), feeding about 0.0014 in/rev.

#52 drill size

A #52 number (wire-gauge) drill is 0.0635 in (1.613 mm). It is the cut tap, 50% thread drill for 1-72.

Decimal inch: 0.0635
Millimeters: 1.613
Nearest 1/64: 1/16" (+0.0010)
Type: number (wire-gauge) drill

Nearest equivalents in other systems

Drills closest to #52
System	Drill	Inch	mm	Difference
Fractional	1/16"	0.0625	1.588	-0.0010 in
Metric	1.6 mm	0.0630	1.600	-0.0005 in

Speeds and feeds: in mild steel an HSS drill starts at about 5,410 RPM and 0.0015 in/rev (8.12 IPM); in 6061 aluminum about 15,040 RPM.

#52 drill speeds and feeds by material

Jobber-length twist drill, D = 0.0635 in. RPM = 3.82 × SFM ÷ D, rounded to 10. Feed per rev scales with diameter and material; IPM = RPM × IPR.

#52 drilling speeds
Material	HSS SFM	HSS RPM	Carbide SFM	Carbide RPM	Feed (in/rev)	HSS IPM	Carbide IPM
Aluminum (6061)	250	15,040	600	36,090	0.0014	21.1	50.5
Brass / free-machining	150	9,020	400	24,060	0.0012	10.8	28.9
Low-carbon steel (1018)	90	5,410	300	18,050	0.0015	8.12	27.1
Alloy steel (4140, annealed)	70	4,210	250	15,040	0.0015	6.32	22.6
Stainless 304	40	2,410	150	9,020	0.0010	2.41	9.02
Gray cast iron	80	4,810	250	15,040	0.0009	4.33	13.5
Titanium 6Al-4V	25	1,500	100	6,020	0.0008	1.20	4.82
Plastics (acetal)	300	18,050	500	30,080	0.0025	45.1	75.2

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, 5,410 RPM × 0.038 mm/rev = 206 mm/min.

Worked example: #52 drill in 1018 steel

HSS drill in low-carbon steel: 90 SFM.
RPM = 3.82 × 90 ÷ 0.0635 ≈ 5,410 RPM.
Feed for a 0.064 in drill in mild steel ≈ 0.0015 in/rev.
IPM = 5,410 × 0.0015 = 8.12 IPM.

Peck cycle by hole depth

#52 drill: depth and canned cycle
Depth	Cycle	Peck	Note
3×D = 0.191 in (4.8 mm)	G81 (no peck)	None	Up to 3×D a sharp drill clears chips on its own.
5×D = 0.318 in (8.1 mm)	G73 chip-break	1 × D	Chip-break pecks; full retract if chips pack (soft aluminum, stainless).
8×D = 0.508 in (12.9 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 #52 drill

1-72 — cut tap, 50% thread · tap speeds and feeds

Nearest drills

1.6 mm: 0.0630 in / 1.600 mm (-0.0005 in)
1/16": 0.0625 in / 1.588 mm (-0.0010 in)
1.65 mm: 0.0650 in / 1.650 mm (+0.0015 in)
1.55 mm: 0.0610 in / 1.550 mm (-0.0025 in)

Drill speed calculator, prefilled for #52 Drill finder: sizes near #52 Number drill chart Decimal equivalent chart

Common questions

What is a #52 drill in decimal and mm?: 0.0635 in, or 1.613 mm; nearest fractional drill: 1/16" (0.0625 in, -0.0010 in); nearest metric drill: 1.6 mm (0.0630 in, -0.0005 in).
What RPM for a #52 drill in steel?: In low-carbon steel (1018) an HSS #52 drill (0.0635 in) runs about 5,410 RPM at 90 SFM; a carbide drill about 18,050 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
What feed for a #52 drill?: About 0.0015 in/rev in mild steel, 0.0014 in/rev in aluminum and 0.0010 in/rev in 304 stainless. At 5,410 RPM that is 8.12 IPM in steel (IPM = RPM × IPR).
What RPM for a #52 drill in aluminum?: 15,040 RPM with HSS (250 SFM) or up to 36,090 RPM with carbide (600 SFM), feeding about 0.0014 in/rev.
What tap uses a #52 drill?: 1-72 (cut tap, 50% 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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