M2.5x0.45 tap drill size

    Use a 2.05 mm drill (2.05 mm) for a M2.5x0.45 cutting tap at 75% thread.

    Drills for M2.5x0.45 (Metric)
    Tap typeDrillDecimal (mm)
    Cutting tap, 75% thread2.05 mm2.05
    Cutting tap, 50% thread (hard material)2.2 mm2.20
    Roll / form tap, 65% thread2.3 mm2.30
    Pitch
    0.45 mm
    Major Ø
    2.50
    Pitch Ø
    2.21
    Minor Ø
    2.01

    M2.5x0.45 tapping speeds and feeds

    Feed = pitch (0.45 mm per rev). Starting points for a general-purpose HSS cut tap:

    • Aluminum 6061 / 7075: 2,720 RPM · 1224 mm/min
    • Free-machining / mild steel: 780 RPM · 351 mm/min
    • 304 / 316 stainless: 390 RPM · 176 mm/min

    M2.5x0.45 tap speeds and feeds: all materials, form taps and G84 code · 2.05 mm drill size and speeds

    Open the tap drill calculatorRoll tap chartHelicoil chart

    Common questions

    What size drill for a M2.5x0.45 tap?
    Use a 2.05 mm drill (2.05 mm) for a M2.5x0.45 cutting tap at 75% thread.
    What drill for a M2.5x0.45 roll (form) tap?
    About 2.30 mm; the nearest standard drill is 2.3 mm. Check your tap maker's table.

    Other Metric 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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