19/32" drill size

    A 19/32" fractional drill is 0.5938 in (15.081 mm). It is the form (roll) tap, 65% thread drill for 5/8-18.

    Decimal inch
    0.5938
    Millimeters
    15.081
    Nearest 1/64
    19/32" (+0.0000)
    Type
    fractional drill

    Nearest equivalents in other systems

    Drills closest to 19/32"
    SystemDrillInchmmDifference
    Number / letterLetter Z0.413010.490-0.1807 in
    Metric15.0 mm0.590615.000-0.0032 in

    Speeds and feeds: in mild steel an HSS drill starts at about 580 RPM and 0.0109 in/rev (6.32 IPM); in 6061 aluminum about 1,610 RPM.

    19/32" drill speeds and feeds by material

    Jobber-length twist drill, D = 0.5938 in. RPM = 3.82 × SFM ÷ D, rounded to 10. Feed per rev scales with diameter and material; IPM = RPM × IPR.

    19/32" drilling speeds
    MaterialHSS SFMHSS RPMCarbide SFMCarbide RPMFeed (in/rev)HSS IPMCarbide IPM
    Aluminum (6061)2501,6106003,8600.010416.740.1
    Brass / free-machining1509604002,5700.00858.1621.9
    Low-carbon steel (1018)905803001,9300.01096.3221.0
    Alloy steel (4140, annealed)704502501,6100.01175.2718.8
    Stainless 304402601509600.00892.318.54
    Gray cast iron805102501,6100.00914.6414.7
    Titanium 6Al-4V251601006400.00520.833.33
    Plastics (acetal)3001,9305003,2200.006412.320.6

    Metric: Vc (m/min) = SFM × 0.3048; feed (mm/rev) = in/rev × 25.4. In steel, 580 RPM × 0.277 mm/rev = 161 mm/min.

    Worked example: 19/32" drill in 1018 steel

    1. HSS drill in low-carbon steel: 90 SFM.
    2. RPM = 3.82 × 90 ÷ 0.5938 ≈ 580 RPM.
    3. Feed for a 0.594 in drill in mild steel ≈ 0.0109 in/rev.
    4. IPM = 580 × 0.0109 = 6.32 IPM.

    Peck cycle by hole depth

    19/32" drill: depth and canned cycle
    DepthCyclePeckNote
    3×D = 1.781 in (45.2 mm)G81 (no peck)NoneUp to 3×D a sharp drill clears chips on its own.
    5×D = 2.969 in (75.4 mm)G73 chip-break1 × DChip-break pecks; full retract if chips pack (soft aluminum, stainless).
    8×D = 4.750 in (120.6 mm)G83 full retract0.5-1 × D, shrinking with depthRetract to clear chips; reduce feed ~10-20% past 5×D.

    Taps that use a 19/32" drill

    Nearest drills

    • 15.0 mm: 0.5906 in / 15.000 mm (-0.0032 in)
    • 15.25 mm: 0.6004 in / 15.250 mm (+0.0066 in)
    • 14.75 mm: 0.5807 in / 14.750 mm (-0.0130 in)
    • 37/64": 0.5781 in / 14.684 mm (-0.0156 in)

    Common questions

    What is a 19/32" drill in decimal and mm?
    0.5938 in, or 15.081 mm; nearest number / letter drill: Letter Z (0.4130 in, -0.1807 in); nearest metric drill: 15.0 mm (0.5906 in, -0.0032 in).
    What RPM for a 19/32" drill in steel?
    In low-carbon steel (1018) an HSS 19/32" drill (0.5938 in) runs about 580 RPM at 90 SFM; a carbide drill about 1,930 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
    What feed for a 19/32" drill?
    About 0.0109 in/rev in mild steel, 0.0104 in/rev in aluminum and 0.0089 in/rev in 304 stainless. At 580 RPM that is 6.32 IPM in steel (IPM = RPM × IPR).
    What RPM for a 19/32" drill in aluminum?
    1,610 RPM with HSS (250 SFM) or up to 3,860 RPM with carbide (600 SFM), feeding about 0.0104 in/rev.
    What tap uses a 19/32" drill?
    5/8-18 (form (roll) tap, 65% thread); 5/8-18 (cut tap, 50% thread); 5/8-24 (cut tap, 50% thread).

    Nearby drill sizes

    Sources

    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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