12-32 tap drill size

    Use a #13 drill (0.1850 in) for a 12-32 cutting tap at 75% thread.

    Drills for 12-32 (UNEF)
    Tap typeDrillDecimal (in)
    Cutting tap, 75% thread#130.1850
    Cutting tap, 50% thread (hard material)#90.1960
    Roll / form tap, 65% thread13/640.2031
    Pitch
    0.7938 mm (32 TPI)
    Major Ø
    0.2160
    Pitch Ø
    0.1957
    Minor Ø
    0.1822

    12-32 tapping speeds and feeds

    Feed = pitch (0.0313 in per rev). Starting points for a general-purpose HSS cut tap:

    • Aluminum 6061 / 7075: 1,240 RPM · 38.8 IPM
    • Free-machining / mild steel: 350 RPM · 10.9 IPM
    • 304 / 316 stainless: 180 RPM · 5.63 IPM

    Tap speeds and feeds by size · #13 drill size and speeds

    Open the tap drill calculatorRoll tap chartHelicoil chart

    Common questions

    What size drill for a 12-32 tap?
    Use a #13 drill (0.1850 in) for a 12-32 cutting tap at 75% thread.
    What drill for a 12-32 roll (form) tap?
    About 0.2022 in; the nearest standard drill is 13/64. Check your tap maker's table.

    Other UNEF sizes

    Drill sizes from Machinery's Handbook and ASME B1.1/B1.13M; roll tap sizes from the form-tap formula. Tap and insert makers' tables are authoritative.

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