What is a 17.25 mm drill in decimal and mm?

0.6791 in, or 17.250 mm; nearest fractional drill: 43/64" (0.6719 in, -0.0073 in); nearest number / letter drill: Letter Z (0.4130 in, -0.2661 in).

What RPM for a 17.25 mm drill in steel?

In low-carbon steel (1018) an HSS 17.25 mm drill (0.6791 in) runs about 510 RPM at 90 SFM; a carbide drill about 1,690 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.

What feed for a 17.25 mm drill?

About 0.0112 in/rev in mild steel, 0.0107 in/rev in aluminum and 0.0092 in/rev in 304 stainless. At 510 RPM that is 5.71 IPM in steel (IPM = RPM × IPR).

What RPM for a 17.25 mm drill in aluminum?

1,410 RPM with HSS (250 SFM) or up to 3,370 RPM with carbide (600 SFM), feeding about 0.0107 in/rev.

What tap uses a 17.25 mm drill?

M18x1.5 (form (roll) tap, 65% thread).

17.25 mm drill size

A 17.25 mm metric drill is 0.6791 in (17.250 mm). It is the form (roll) tap, 65% thread drill for M18x1.5.

Decimal inch: 0.6791
Millimeters: 17.250
Nearest 1/64: 43/64" (+0.0073)
Type: metric drill

Nearest equivalents in other systems

Drills closest to 17.25 mm
System	Drill	Inch	mm	Difference
Fractional	43/64"	0.6719	17.066	-0.0073 in
Number / letter	Letter Z	0.4130	10.490	-0.2661 in

Speeds and feeds: in mild steel an HSS drill starts at about 510 RPM and 0.0112 in/rev (5.71 IPM); in 6061 aluminum about 1,410 RPM.

17.25 mm drill speeds and feeds by material

Jobber-length twist drill, D = 0.6791 in. RPM = 3.82 × SFM ÷ D, rounded to 10. Feed per rev scales with diameter and material; IPM = RPM × IPR.

17.25 mm drilling speeds
Material	HSS SFM	HSS RPM	Carbide SFM	Carbide RPM	Feed (in/rev)	HSS IPM	Carbide IPM
Aluminum (6061)	250	1,410	600	3,370	0.0107	15.1	36.1
Brass / free-machining	150	840	400	2,250	0.0088	7.39	19.8
Low-carbon steel (1018)	90	510	300	1,690	0.0112	5.71	18.9
Alloy steel (4140, annealed)	70	390	250	1,410	0.0119	4.64	16.8
Stainless 304	40	220	150	840	0.0092	2.02	7.73
Gray cast iron	80	450	250	1,410	0.0096	4.32	13.5
Titanium 6Al-4V	25	140	100	560	0.0054	0.76	3.02
Plastics (acetal)	300	1,690	500	2,810	0.0067	11.3	18.8

Metric: Vc (m/min) = SFM × 0.3048; feed (mm/rev) = in/rev × 25.4. In steel, 510 RPM × 0.284 mm/rev = 145 mm/min.

Worked example: 17.25 mm drill in 1018 steel

HSS drill in low-carbon steel: 90 SFM.
RPM = 3.82 × 90 ÷ 0.6791 ≈ 510 RPM.
Feed for a 0.679 in drill in mild steel ≈ 0.0112 in/rev.
IPM = 510 × 0.0112 = 5.71 IPM.

Peck cycle by hole depth

17.25 mm drill: depth and canned cycle
Depth	Cycle	Peck	Note
3×D = 2.037 in (51.8 mm)	G81 (no peck)	None	Up to 3×D a sharp drill clears chips on its own.
5×D = 3.396 in (86.3 mm)	G73 chip-break	1 × D	Chip-break pecks; full retract if chips pack (soft aluminum, stainless).
8×D = 5.433 in (138 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 17.25 mm drill

M18x1.5 — form (roll) tap, 65% thread

Nearest drills

43/64": 0.6719 in / 17.066 mm (-0.0073 in)
11/16": 0.6875 in / 17.463 mm (+0.0084 in)
17.0 mm: 0.6693 in / 17.000 mm (-0.0098 in)
17.5 mm: 0.6890 in / 17.500 mm (+0.0098 in)

Drill speed calculator, prefilled for 17.25 mm Drill finder: sizes near 17.25 mm Metric drill chart Decimal equivalent chart

Common questions

What is a 17.25 mm drill in decimal and mm?: 0.6791 in, or 17.250 mm; nearest fractional drill: 43/64" (0.6719 in, -0.0073 in); nearest number / letter drill: Letter Z (0.4130 in, -0.2661 in).
What RPM for a 17.25 mm drill in steel?: In low-carbon steel (1018) an HSS 17.25 mm drill (0.6791 in) runs about 510 RPM at 90 SFM; a carbide drill about 1,690 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
What feed for a 17.25 mm drill?: About 0.0112 in/rev in mild steel, 0.0107 in/rev in aluminum and 0.0092 in/rev in 304 stainless. At 510 RPM that is 5.71 IPM in steel (IPM = RPM × IPR).
What RPM for a 17.25 mm drill in aluminum?: 1,410 RPM with HSS (250 SFM) or up to 3,370 RPM with carbide (600 SFM), feeding about 0.0107 in/rev.
What tap uses a 17.25 mm drill?: M18x1.5 (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.

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