What is a 19/64" drill in decimal and mm?

0.2969 in, or 7.541 mm; nearest number / letter drill: Letter M (0.2950 in, -0.0019 in); nearest metric drill: 7.5 mm (0.2953 in, -0.0016 in).

What RPM for a 19/64" drill in steel?

In low-carbon steel (1018) an HSS 19/64" drill (0.2969 in) runs about 1,160 RPM at 90 SFM; a carbide drill about 3,860 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.

What feed for a 19/64" drill?

About 0.0076 in/rev in mild steel, 0.0069 in/rev in aluminum and 0.0050 in/rev in 304 stainless. At 1,160 RPM that is 8.82 IPM in steel (IPM = RPM × IPR).

What RPM for a 19/64" drill in aluminum?

3,220 RPM with HSS (250 SFM) or up to 7,720 RPM with carbide (600 SFM), feeding about 0.0069 in/rev.

What tap uses a 19/64" drill?

5/16-32 (form (roll) tap, 65% thread).

19/64" drill size

A 19/64" fractional drill is 0.2969 in (7.541 mm). It is the form (roll) tap, 65% thread drill for 5/16-32.

Decimal inch: 0.2969
Millimeters: 7.541
Nearest 1/64: 19/64" (+0.0000)
Type: fractional drill

Nearest equivalents in other systems

Drills closest to 19/64"
System	Drill	Inch	mm	Difference
Number / letter	Letter M	0.2950	7.493	-0.0019 in
Metric	7.5 mm	0.2953	7.500	-0.0016 in

Speeds and feeds: in mild steel an HSS drill starts at about 1,160 RPM and 0.0076 in/rev (8.82 IPM); in 6061 aluminum about 3,220 RPM.

19/64" drill speeds and feeds by material

Jobber-length twist drill, D = 0.2969 in. RPM = 3.82 × SFM ÷ D, rounded to 10. Feed per rev scales with diameter and material; IPM = RPM × IPR.

19/64" drilling speeds
Material	HSS SFM	HSS RPM	Carbide SFM	Carbide RPM	Feed (in/rev)	HSS IPM	Carbide IPM
Aluminum (6061)	250	3,220	600	7,720	0.0069	22.2	53.3
Brass / free-machining	150	1,930	400	5,150	0.0056	10.8	28.8
Low-carbon steel (1018)	90	1,160	300	3,860	0.0076	8.82	29.3
Alloy steel (4140, annealed)	70	900	250	3,220	0.0080	7.20	25.8
Stainless 304	40	510	150	1,930	0.0050	2.55	9.65
Gray cast iron	80	1,030	250	3,220	0.0052	5.36	16.7
Titanium 6Al-4V	25	320	100	1,290	0.0035	1.12	4.51
Plastics (acetal)	300	3,860	500	6,430	0.0044	17.0	28.3

Metric: Vc (m/min) = SFM × 0.3048; feed (mm/rev) = in/rev × 25.4. In steel, 1,160 RPM × 0.193 mm/rev = 224 mm/min.

Worked example: 19/64" drill in 1018 steel

HSS drill in low-carbon steel: 90 SFM.
RPM = 3.82 × 90 ÷ 0.2969 ≈ 1,160 RPM.
Feed for a 0.297 in drill in mild steel ≈ 0.0076 in/rev.
IPM = 1,160 × 0.0076 = 8.82 IPM.

Peck cycle by hole depth

19/64" drill: depth and canned cycle
Depth	Cycle	Peck	Note
3×D = 0.891 in (22.6 mm)	G81 (no peck)	None	Up to 3×D a sharp drill clears chips on its own.
5×D = 1.484 in (37.7 mm)	G73 chip-break	1 × D	Chip-break pecks; full retract if chips pack (soft aluminum, stainless).
8×D = 2.375 in (60.3 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 19/64" drill

5/16-32 — form (roll) tap, 65% thread

Nearest drills

7.5 mm: 0.2953 in / 7.500 mm (-0.0016 in)
Letter M: 0.2950 in / 7.493 mm (-0.0019 in)
7.6 mm: 0.2992 in / 7.600 mm (+0.0023 in)
Letter N: 0.3020 in / 7.671 mm (+0.0051 in)

Drill speed calculator, prefilled for 19/64"Drill finder: sizes near 19/64"Fractional drill chart Decimal equivalent chart

Common questions

What is a 19/64" drill in decimal and mm?: 0.2969 in, or 7.541 mm; nearest number / letter drill: Letter M (0.2950 in, -0.0019 in); nearest metric drill: 7.5 mm (0.2953 in, -0.0016 in).
What RPM for a 19/64" drill in steel?: In low-carbon steel (1018) an HSS 19/64" drill (0.2969 in) runs about 1,160 RPM at 90 SFM; a carbide drill about 3,860 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
What feed for a 19/64" drill?: About 0.0076 in/rev in mild steel, 0.0069 in/rev in aluminum and 0.0050 in/rev in 304 stainless. At 1,160 RPM that is 8.82 IPM in steel (IPM = RPM × IPR).
What RPM for a 19/64" drill in aluminum?: 3,220 RPM with HSS (250 SFM) or up to 7,720 RPM with carbide (600 SFM), feeding about 0.0069 in/rev.
What tap uses a 19/64" drill?: 5/16-32 (form (roll) tap, 65% 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.

Free for machinists & programmers

Put your skills on a free talent profile

Machines, controls, certs and saved calculations in one profile shops can find.

Create free profile

For your shop

Bring shift handoffs to your shop

Stop losing job status between shifts. Every station's notes, counts and issues, handed off cleanly.

See shift handoffs