What is a #29 drill in decimal and mm?

0.1360 in, or 3.454 mm; nearest fractional drill: 9/64" (0.1406 in, +0.0046 in); nearest metric drill: 3.5 mm (0.1378 in, +0.0018 in).

What RPM for a #29 drill in steel?

In low-carbon steel (1018) an HSS #29 drill (0.1360 in) runs about 2,530 RPM at 90 SFM; a carbide drill about 8,430 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.

What feed for a #29 drill?

About 0.0033 in/rev in mild steel, 0.0031 in/rev in aluminum and 0.0022 in/rev in 304 stainless. At 2,530 RPM that is 8.35 IPM in steel (IPM = RPM × IPR).

What RPM for a #29 drill in aluminum?

7,020 RPM with HSS (250 SFM) or up to 16,850 RPM with carbide (600 SFM), feeding about 0.0031 in/rev.

What tap uses a #29 drill?

8-32 (cut tap, 75% thread); 8-36 (cut tap, 75% thread); 5-40 (Helicoil / STI insert (#5-40×1D)).

#29 drill size

A #29 number (wire-gauge) drill is 0.1360 in (3.454 mm). It is the cut tap, 75% thread drill for 8-32.

Decimal inch: 0.1360
Millimeters: 3.454
Nearest 1/64: 9/64" (-0.0046)
Type: number (wire-gauge) drill

Nearest equivalents in other systems

Drills closest to #29
System	Drill	Inch	mm	Difference
Fractional	9/64"	0.1406	3.572	+0.0046 in
Metric	3.5 mm	0.1378	3.500	+0.0018 in

Speeds and feeds: in mild steel an HSS drill starts at about 2,530 RPM and 0.0033 in/rev (8.35 IPM); in 6061 aluminum about 7,020 RPM.

#29 drill speeds and feeds by material

Jobber-length twist drill, D = 0.1360 in. RPM = 3.82 × SFM ÷ D, rounded to 10. Feed per rev scales with diameter and material; IPM = RPM × IPR.

#29 drilling speeds
Material	HSS SFM	HSS RPM	Carbide SFM	Carbide RPM	Feed (in/rev)	HSS IPM	Carbide IPM
Aluminum (6061)	250	7,020	600	16,850	0.0031	21.8	52.2
Brass / free-machining	150	4,210	400	11,230	0.0027	11.4	30.3
Low-carbon steel (1018)	90	2,530	300	8,430	0.0033	8.35	27.8
Alloy steel (4140, annealed)	70	1,970	250	7,020	0.0033	6.50	23.2
Stainless 304	40	1,120	150	4,210	0.0022	2.46	9.26
Gray cast iron	80	2,250	250	7,020	0.0020	4.50	14.0
Titanium 6Al-4V	25	700	100	2,810	0.0017	1.19	4.78
Plastics (acetal)	300	8,430	500	14,040	0.0049	41.3	68.8

Metric: Vc (m/min) = SFM × 0.3048; feed (mm/rev) = in/rev × 25.4. In steel, 2,530 RPM × 0.084 mm/rev = 212 mm/min.

Worked example: #29 drill in 1018 steel

HSS drill in low-carbon steel: 90 SFM.
RPM = 3.82 × 90 ÷ 0.1360 ≈ 2,530 RPM.
Feed for a 0.136 in drill in mild steel ≈ 0.0033 in/rev.
IPM = 2,530 × 0.0033 = 8.35 IPM.

Peck cycle by hole depth

#29 drill: depth and canned cycle
Depth	Cycle	Peck	Note
3×D = 0.408 in (10.4 mm)	G81 (no peck)	None	Up to 3×D a sharp drill clears chips on its own.
5×D = 0.680 in (17.3 mm)	G73 chip-break	1 × D	Chip-break pecks; full retract if chips pack (soft aluminum, stainless).
8×D = 1.088 in (27.6 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 #29 drill

8-32 — cut tap, 75% thread · tap speeds and feeds
8-36 — cut tap, 75% thread · tap speeds and feeds
5-40 — Helicoil / STI insert (#5-40×1D) · tap speeds and feeds

Nearest drills

3.5 mm: 0.1378 in / 3.500 mm (+0.0018 in)
3.4 mm: 0.1339 in / 3.400 mm (-0.0021 in)
#28: 0.1405 in / 3.569 mm (+0.0045 in)
9/64": 0.1406 in / 3.572 mm (+0.0046 in)

Drill speed calculator, prefilled for #29 Drill finder: sizes near #29 Number drill chart Decimal equivalent chart

Common questions

What is a #29 drill in decimal and mm?: 0.1360 in, or 3.454 mm; nearest fractional drill: 9/64" (0.1406 in, +0.0046 in); nearest metric drill: 3.5 mm (0.1378 in, +0.0018 in).
What RPM for a #29 drill in steel?: In low-carbon steel (1018) an HSS #29 drill (0.1360 in) runs about 2,530 RPM at 90 SFM; a carbide drill about 8,430 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
What feed for a #29 drill?: About 0.0033 in/rev in mild steel, 0.0031 in/rev in aluminum and 0.0022 in/rev in 304 stainless. At 2,530 RPM that is 8.35 IPM in steel (IPM = RPM × IPR).
What RPM for a #29 drill in aluminum?: 7,020 RPM with HSS (250 SFM) or up to 16,850 RPM with carbide (600 SFM), feeding about 0.0031 in/rev.
What tap uses a #29 drill?: 8-32 (cut tap, 75% thread); 8-36 (cut tap, 75% thread); 5-40 (Helicoil / STI insert (#5-40×1D)).

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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