What is a 15.0 mm drill in decimal and mm?

0.5906 in, or 15.000 mm; nearest fractional drill: 19/32" (0.5938 in, +0.0032 in); nearest number / letter drill: Letter Z (0.4130 in, -0.1776 in).

What RPM for a 15.0 mm drill in steel?

In low-carbon steel (1018) an HSS 15.0 mm drill (0.5906 in) runs about 580 RPM at 90 SFM; a carbide drill about 1,940 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.

What feed for a 15.0 mm drill?

About 0.0109 in/rev in mild steel, 0.0104 in/rev in aluminum and 0.0089 in/rev in 304 stainless. At 580 RPM that is 6.32 IPM in steel (IPM = RPM × IPR).

What RPM for a 15.0 mm drill in aluminum?

1,620 RPM with HSS (250 SFM) or up to 3,880 RPM with carbide (600 SFM), feeding about 0.0104 in/rev.

What tap uses a 15.0 mm drill?

M16x1.5 (cut tap, 50% thread); M14×2.0 (Helicoil / STI insert (M14×2.0×1D)).

15.0 mm drill size

A 15.0 mm metric drill is 0.5906 in (15.000 mm). It is the cut tap, 50% thread drill for M16x1.5.

Decimal inch: 0.5906
Millimeters: 15.000
Nearest 1/64: 19/32" (-0.0032)
Type: metric drill

Nearest equivalents in other systems

Drills closest to 15.0 mm
System	Drill	Inch	mm	Difference
Fractional	19/32"	0.5938	15.081	+0.0032 in
Number / letter	Letter Z	0.4130	10.490	-0.1776 in

Speeds and feeds: in mild steel an HSS drill starts at about 580 RPM and 0.0109 in/rev (6.32 IPM); in 6061 aluminum about 1,620 RPM.

15.0 mm drill speeds and feeds by material

Jobber-length twist drill, D = 0.5906 in. RPM = 3.82 × SFM ÷ D, rounded to 10. Feed per rev scales with diameter and material; IPM = RPM × IPR.

15.0 mm drilling speeds
Material	HSS SFM	HSS RPM	Carbide SFM	Carbide RPM	Feed (in/rev)	HSS IPM	Carbide IPM
Aluminum (6061)	250	1,620	600	3,880	0.0104	16.9	40.4
Brass / free-machining	150	970	400	2,590	0.0085	8.25	22.0
Low-carbon steel (1018)	90	580	300	1,940	0.0109	6.32	21.1
Alloy steel (4140, annealed)	70	450	250	1,620	0.0117	5.27	18.9
Stainless 304	40	260	150	970	0.0089	2.31	8.63
Gray cast iron	80	520	250	1,620	0.0090	4.68	14.6
Titanium 6Al-4V	25	160	100	650	0.0052	0.83	3.38
Plastics (acetal)	300	1,940	500	3,230	0.0064	12.4	20.7

Metric: Vc (m/min) = SFM × 0.3048; feed (mm/rev) = in/rev × 25.4. In steel, 580 RPM × 0.277 mm/rev = 161 mm/min.

Worked example: 15.0 mm drill in 1018 steel

HSS drill in low-carbon steel: 90 SFM.
RPM = 3.82 × 90 ÷ 0.5906 ≈ 580 RPM.
Feed for a 0.591 in drill in mild steel ≈ 0.0109 in/rev.
IPM = 580 × 0.0109 = 6.32 IPM.

Peck cycle by hole depth

15.0 mm drill: depth and canned cycle
Depth	Cycle	Peck	Note
3×D = 1.772 in (45 mm)	G81 (no peck)	None	Up to 3×D a sharp drill clears chips on its own.
5×D = 2.953 in (75 mm)	G73 chip-break	1 × D	Chip-break pecks; full retract if chips pack (soft aluminum, stainless).
8×D = 4.724 in (120 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 15.0 mm drill

M16x1.5 — cut tap, 50% thread
M14×2.0 — Helicoil / STI insert (M14×2.0×1D) · tap speeds and feeds

Nearest drills

19/32": 0.5938 in / 15.081 mm (+0.0032 in)
14.75 mm: 0.5807 in / 14.750 mm (-0.0098 in)
15.25 mm: 0.6004 in / 15.250 mm (+0.0098 in)
37/64": 0.5781 in / 14.684 mm (-0.0124 in)

Drill speed calculator, prefilled for 15.0 mm Drill finder: sizes near 15.0 mm Metric drill chart Decimal equivalent chart

Common questions

What is a 15.0 mm drill in decimal and mm?: 0.5906 in, or 15.000 mm; nearest fractional drill: 19/32" (0.5938 in, +0.0032 in); nearest number / letter drill: Letter Z (0.4130 in, -0.1776 in).
What RPM for a 15.0 mm drill in steel?: In low-carbon steel (1018) an HSS 15.0 mm drill (0.5906 in) runs about 580 RPM at 90 SFM; a carbide drill about 1,940 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
What feed for a 15.0 mm drill?: About 0.0109 in/rev in mild steel, 0.0104 in/rev in aluminum and 0.0089 in/rev in 304 stainless. At 580 RPM that is 6.32 IPM in steel (IPM = RPM × IPR).
What RPM for a 15.0 mm drill in aluminum?: 1,620 RPM with HSS (250 SFM) or up to 3,880 RPM with carbide (600 SFM), feeding about 0.0104 in/rev.
What tap uses a 15.0 mm drill?: M16x1.5 (cut tap, 50% thread); M14×2.0 (Helicoil / STI insert (M14×2.0×1D)).

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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