What is a 3/16" drill in decimal and mm?

0.1875 in, or 4.762 mm; nearest number / letter drill: #12 (0.1890 in, +0.0015 in); nearest metric drill: 4.8 mm (0.1890 in, +0.0015 in).

What RPM for a 3/16" drill in steel?

In low-carbon steel (1018) an HSS 3/16" drill (0.1875 in) runs about 1,830 RPM at 90 SFM; a carbide drill about 6,110 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.

What feed for a 3/16" drill?

About 0.0047 in/rev in mild steel, 0.0044 in/rev in aluminum and 0.0031 in/rev in 304 stainless. At 1,830 RPM that is 8.60 IPM in steel (IPM = RPM × IPR).

What RPM for a 3/16" drill in aluminum?

5,090 RPM with HSS (250 SFM) or up to 12,220 RPM with carbide (600 SFM), feeding about 0.0044 in/rev.

What size is a 3/16" drill?

0.1875 in / 4.762 mm. The nearest other drills are 4.8 mm (0.1890 in), #12 (0.1890 in), 4.7 mm (0.1850 in).

3/16" drill size

A 3/16" fractional drill is 0.1875 in (4.762 mm).

Decimal inch: 0.1875
Millimeters: 4.762
Nearest 1/64: 3/16" (+0.0000)
Type: fractional drill

Nearest equivalents in other systems

Drills closest to 3/16"
System	Drill	Inch	mm	Difference
Number / letter	#12	0.1890	4.801	+0.0015 in
Metric	4.8 mm	0.1890	4.800	+0.0015 in

Speeds and feeds: in mild steel an HSS drill starts at about 1,830 RPM and 0.0047 in/rev (8.60 IPM); in 6061 aluminum about 5,090 RPM.

3/16" drill speeds and feeds by material

Jobber-length twist drill, D = 0.1875 in. RPM = 3.82 × SFM ÷ D, rounded to 10. Feed per rev scales with diameter and material; IPM = RPM × IPR.

3/16" drilling speeds
Material	HSS SFM	HSS RPM	Carbide SFM	Carbide RPM	Feed (in/rev)	HSS IPM	Carbide IPM
Aluminum (6061)	250	5,090	600	12,220	0.0044	22.4	53.8
Brass / free-machining	150	3,060	400	8,150	0.0038	11.6	31.0
Low-carbon steel (1018)	90	1,830	300	6,110	0.0047	8.60	28.7
Alloy steel (4140, annealed)	70	1,430	250	5,090	0.0047	6.72	23.9
Stainless 304	40	810	150	3,060	0.0031	2.51	9.49
Gray cast iron	80	1,630	250	5,090	0.0032	5.22	16.3
Titanium 6Al-4V	25	510	100	2,040	0.0023	1.17	4.69
Plastics (acetal)	300	6,110	500	10,190	0.0045	27.5	45.9

Metric: Vc (m/min) = SFM × 0.3048; feed (mm/rev) = in/rev × 25.4. In steel, 1,830 RPM × 0.119 mm/rev = 218 mm/min.

Worked example: 3/16" drill in 1018 steel

HSS drill in low-carbon steel: 90 SFM.
RPM = 3.82 × 90 ÷ 0.1875 ≈ 1,830 RPM.
Feed for a 0.188 in drill in mild steel ≈ 0.0047 in/rev.
IPM = 1,830 × 0.0047 = 8.60 IPM.

Peck cycle by hole depth

3/16" drill: depth and canned cycle
Depth	Cycle	Peck	Note
3×D = 0.563 in (14.3 mm)	G81 (no peck)	None	Up to 3×D a sharp drill clears chips on its own.
5×D = 0.938 in (23.8 mm)	G73 chip-break	1 × D	Chip-break pecks; full retract if chips pack (soft aluminum, stainless).
8×D = 1.500 in (38.1 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 3/16" drill

No standard UNC, UNF or metric tap in our tables calls for a 3/16" drill. Use it for clearance, pilot or reamer prep holes.

Nearest drills

4.8 mm: 0.1890 in / 4.800 mm (+0.0015 in)
#12: 0.1890 in / 4.801 mm (+0.0015 in)
4.7 mm: 0.1850 in / 4.700 mm (-0.0025 in)
#13: 0.1850 in / 4.699 mm (-0.0025 in)

Drill speed calculator, prefilled for 3/16"Drill finder: sizes near 3/16"Fractional drill chart Decimal equivalent chart

Common questions

What is a 3/16" drill in decimal and mm?: 0.1875 in, or 4.762 mm; nearest number / letter drill: #12 (0.1890 in, +0.0015 in); nearest metric drill: 4.8 mm (0.1890 in, +0.0015 in).
What RPM for a 3/16" drill in steel?: In low-carbon steel (1018) an HSS 3/16" drill (0.1875 in) runs about 1,830 RPM at 90 SFM; a carbide drill about 6,110 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
What feed for a 3/16" drill?: About 0.0047 in/rev in mild steel, 0.0044 in/rev in aluminum and 0.0031 in/rev in 304 stainless. At 1,830 RPM that is 8.60 IPM in steel (IPM = RPM × IPR).
What RPM for a 3/16" drill in aluminum?: 5,090 RPM with HSS (250 SFM) or up to 12,220 RPM with carbide (600 SFM), feeding about 0.0044 in/rev.
What size is a 3/16" drill?: 0.1875 in / 4.762 mm. The nearest other drills are 4.8 mm (0.1890 in), #12 (0.1890 in), 4.7 mm (0.1850 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.

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