What is a 1.35 mm drill in decimal and mm?

0.0532 in, or 1.350 mm; nearest fractional drill: 3/64" (0.0469 in, -0.0063 in); nearest number / letter drill: #55 (0.0520 in, -0.0011 in).

What RPM for a 1.35 mm drill in steel?

In low-carbon steel (1018) an HSS 1.35 mm drill (0.0532 in) runs about 6,470 RPM at 90 SFM; a carbide drill about 21,560 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.

What feed for a 1.35 mm drill?

About 0.0013 in/rev in mild steel, 0.0012 in/rev in aluminum and 0.0009 in/rev in 304 stainless. At 6,470 RPM that is 8.41 IPM in steel (IPM = RPM × IPR).

What RPM for a 1.35 mm drill in aluminum?

17,970 RPM with HSS (250 SFM) or up to 43,120 RPM with carbide (600 SFM), feeding about 0.0012 in/rev.

What tap uses a 1.35 mm drill?

M1.6x0.35 (cut tap, 50% thread).

1.35 mm drill size

A 1.35 mm metric drill is 0.0532 in (1.350 mm). It is the cut tap, 50% thread drill for M1.6x0.35.

Decimal inch: 0.0532
Millimeters: 1.350
Nearest 1/64: 3/64" (+0.0063)
Type: metric drill

Nearest equivalents in other systems

Drills closest to 1.35 mm
System	Drill	Inch	mm	Difference
Fractional	3/64"	0.0469	1.191	-0.0063 in
Number / letter	#55	0.0520	1.321	-0.0011 in

Speeds and feeds: in mild steel an HSS drill starts at about 6,470 RPM and 0.0013 in/rev (8.41 IPM); in 6061 aluminum about 17,970 RPM.

1.35 mm drill speeds and feeds by material

Jobber-length twist drill, D = 0.0532 in. RPM = 3.82 × SFM ÷ D, rounded to 10. Feed per rev scales with diameter and material; IPM = RPM × IPR.

1.35 mm drilling speeds
Material	HSS SFM	HSS RPM	Carbide SFM	Carbide RPM	Feed (in/rev)	HSS IPM	Carbide IPM
Aluminum (6061)	250	17,970	600	43,120	0.0012	21.6	51.7
Brass / free-machining	150	10,780	400	28,750	0.0010	10.8	28.8
Low-carbon steel (1018)	90	6,470	300	21,560	0.0013	8.41	28.0
Alloy steel (4140, annealed)	70	5,030	250	17,970	0.0013	6.54	23.4
Stainless 304	40	2,870	150	10,780	0.0009	2.58	9.70
Gray cast iron	80	5,750	250	17,970	0.0008	4.60	14.4
Titanium 6Al-4V	25	1,800	100	7,190	0.0007	1.26	5.03
Plastics (acetal)	300	21,560	500	35,930	0.0021	45.3	75.5

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, 6,470 RPM × 0.033 mm/rev = 214 mm/min.

Worked example: 1.35 mm drill in 1018 steel

HSS drill in low-carbon steel: 90 SFM.
RPM = 3.82 × 90 ÷ 0.0532 ≈ 6,470 RPM.
Feed for a 0.053 in drill in mild steel ≈ 0.0013 in/rev.
IPM = 6,470 × 0.0013 = 8.41 IPM.

Peck cycle by hole depth

1.35 mm drill: depth and canned cycle
Depth	Cycle	Peck	Note
3×D = 0.159 in (4.1 mm)	G81 (no peck)	None	Up to 3×D a sharp drill clears chips on its own.
5×D = 0.266 in (6.8 mm)	G73 chip-break	1 × D	Chip-break pecks; full retract if chips pack (soft aluminum, stainless).
8×D = 0.425 in (10.8 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 1.35 mm drill

M1.6x0.35 — cut tap, 50% thread · tap speeds and feeds

Nearest drills

#55: 0.0520 in / 1.321 mm (-0.0011 in)
#54: 0.0550 in / 1.397 mm (+0.0019 in)
1.3 mm: 0.0512 in / 1.300 mm (-0.0020 in)
1.4 mm: 0.0551 in / 1.400 mm (+0.0020 in)

Drill speed calculator, prefilled for 1.35 mm Drill finder: sizes near 1.35 mm Metric drill chart Decimal equivalent chart

Common questions

What is a 1.35 mm drill in decimal and mm?: 0.0532 in, or 1.350 mm; nearest fractional drill: 3/64" (0.0469 in, -0.0063 in); nearest number / letter drill: #55 (0.0520 in, -0.0011 in).
What RPM for a 1.35 mm drill in steel?: In low-carbon steel (1018) an HSS 1.35 mm drill (0.0532 in) runs about 6,470 RPM at 90 SFM; a carbide drill about 21,560 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
What feed for a 1.35 mm drill?: About 0.0013 in/rev in mild steel, 0.0012 in/rev in aluminum and 0.0009 in/rev in 304 stainless. At 6,470 RPM that is 8.41 IPM in steel (IPM = RPM × IPR).
What RPM for a 1.35 mm drill in aluminum?: 17,970 RPM with HSS (250 SFM) or up to 43,120 RPM with carbide (600 SFM), feeding about 0.0012 in/rev.
What tap uses a 1.35 mm drill?: M1.6x0.35 (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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