What is a 7/16" drill in decimal and mm?

0.4375 in, or 11.112 mm; nearest number / letter drill: Letter Z (0.4130 in, -0.0245 in); nearest metric drill: 11.1 mm (0.4370 in, -0.0005 in).

What RPM for a 7/16" drill in steel?

In low-carbon steel (1018) an HSS 7/16" drill (0.4375 in) runs about 790 RPM at 90 SFM; a carbide drill about 2,620 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.

What feed for a 7/16" drill?

About 0.0100 in/rev in mild steel, 0.0093 in/rev in aluminum and 0.0074 in/rev in 304 stainless. At 790 RPM that is 7.90 IPM in steel (IPM = RPM × IPR).

What RPM for a 7/16" drill in aluminum?

2,180 RPM with HSS (250 SFM) or up to 5,240 RPM with carbide (600 SFM), feeding about 0.0093 in/rev.

What size is a 7/16" drill?

0.4375 in / 11.11 mm. The nearest other drills are 11.1 mm (0.4370 in), 11.2 mm (0.4409 in), 11.0 mm (0.4331 in).

7/16" drill size

A 7/16" fractional drill is 0.4375 in (11.112 mm).

Decimal inch: 0.4375
Millimeters: 11.112
Nearest 1/64: 7/16" (+0.0000)
Type: fractional drill

Nearest equivalents in other systems

Drills closest to 7/16"
System	Drill	Inch	mm	Difference
Number / letter	Letter Z	0.4130	10.490	-0.0245 in
Metric	11.1 mm	0.4370	11.100	-0.0005 in

Speeds and feeds: in mild steel an HSS drill starts at about 790 RPM and 0.0100 in/rev (7.90 IPM); in 6061 aluminum about 2,180 RPM.

7/16" drill speeds and feeds by material

Jobber-length twist drill, D = 0.4375 in. RPM = 3.82 × SFM ÷ D, rounded to 10. Feed per rev scales with diameter and material; IPM = RPM × IPR.

7/16" drilling speeds
Material	HSS SFM	HSS RPM	Carbide SFM	Carbide RPM	Feed (in/rev)	HSS IPM	Carbide IPM
Aluminum (6061)	250	2,180	600	5,240	0.0093	20.3	48.7
Brass / free-machining	150	1,310	400	3,490	0.0073	9.56	25.5
Low-carbon steel (1018)	90	790	300	2,620	0.0100	7.90	26.2
Alloy steel (4140, annealed)	70	610	250	2,180	0.0110	6.71	24.0
Stainless 304	40	350	150	1,310	0.0074	2.59	9.69
Gray cast iron	80	700	250	2,180	0.0075	5.25	16.4
Titanium 6Al-4V	25	220	100	870	0.0046	1.01	4.00
Plastics (acetal)	300	2,620	500	4,370	0.0055	14.4	24.0

Metric: Vc (m/min) = SFM × 0.3048; feed (mm/rev) = in/rev × 25.4. In steel, 790 RPM × 0.254 mm/rev = 201 mm/min.

Worked example: 7/16" drill in 1018 steel

HSS drill in low-carbon steel: 90 SFM.
RPM = 3.82 × 90 ÷ 0.4375 ≈ 790 RPM.
Feed for a 0.438 in drill in mild steel ≈ 0.0100 in/rev.
IPM = 790 × 0.0100 = 7.90 IPM.

Peck cycle by hole depth

7/16" drill: depth and canned cycle
Depth	Cycle	Peck	Note
3×D = 1.313 in (33.3 mm)	G81 (no peck)	None	Up to 3×D a sharp drill clears chips on its own.
5×D = 2.188 in (55.6 mm)	G73 chip-break	1 × D	Chip-break pecks; full retract if chips pack (soft aluminum, stainless).
8×D = 3.500 in (88.9 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 7/16" drill

No standard UNC, UNF or metric tap in our tables calls for a 7/16" drill. Use it for clearance, pilot or reamer prep holes.

Nearest drills

11.1 mm: 0.4370 in / 11.100 mm (-0.0005 in)
11.2 mm: 0.4409 in / 11.200 mm (+0.0034 in)
11.0 mm: 0.4331 in / 11.000 mm (-0.0044 in)
11.3 mm: 0.4449 in / 11.300 mm (+0.0074 in)

Drill speed calculator, prefilled for 7/16"Drill finder: sizes near 7/16"Fractional drill chart Decimal equivalent chart

Common questions

What is a 7/16" drill in decimal and mm?: 0.4375 in, or 11.112 mm; nearest number / letter drill: Letter Z (0.4130 in, -0.0245 in); nearest metric drill: 11.1 mm (0.4370 in, -0.0005 in).
What RPM for a 7/16" drill in steel?: In low-carbon steel (1018) an HSS 7/16" drill (0.4375 in) runs about 790 RPM at 90 SFM; a carbide drill about 2,620 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
What feed for a 7/16" drill?: About 0.0100 in/rev in mild steel, 0.0093 in/rev in aluminum and 0.0074 in/rev in 304 stainless. At 790 RPM that is 7.90 IPM in steel (IPM = RPM × IPR).
What RPM for a 7/16" drill in aluminum?: 2,180 RPM with HSS (250 SFM) or up to 5,240 RPM with carbide (600 SFM), feeding about 0.0093 in/rev.
What size is a 7/16" drill?: 0.4375 in / 11.11 mm. The nearest other drills are 11.1 mm (0.4370 in), 11.2 mm (0.4409 in), 11.0 mm (0.4331 in).

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