Metric tap drill chart (coarse and fine)

    ISO metric threads from M1.6 to M36 in coarse and common fine pitches. The standard tap drill is major diameter minus pitch; the other columns give the nearest standard metric drill for each thread percentage.

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    ISO metric coarse tap drills
    ThreadStandard drill (mm)75% drill65% drill50% drillForm tap (65%)Minor dia (mm)
    M1.6x0.35 1.25 (77%)1.25 mm 1.25 · 77%1.3 mm 1.30 · 66%1.35 mm 1.35 · 55%1.45 mm 1.451.22
    M2x0.4 1.60 (77%)1.6 mm 1.60 · 77%1.65 mm 1.65 · 67.4%1.75 mm 1.75 · 48.1%1.8 mm 1.801.57
    M2.5x0.45 2.05 (77%)2.05 mm 2.05 · 77%2.1 mm 2.10 · 68.4%2.2 mm 2.20 · 51.3%2.3 mm 2.302.01
    M3x0.5 2.50 (77%)2.5 mm 2.50 · 77%2.6 mm 2.60 · 61.6%2.7 mm 2.70 · 46.2%2.8 mm 2.802.46
    M3.5x0.6 2.90 (77%)2.9 mm 2.90 · 77%3.0 mm 3.00 · 64.2%3.1 mm 3.10 · 51.3%3.2 mm 3.202.85
    M4x0.7 3.30 (77%)3.3 mm 3.30 · 77%3.4 mm 3.40 · 66%3.5 mm 3.50 · 55%3.7 mm 3.703.24
    M5x0.8 4.20 (77%)4.2 mm 4.20 · 77%4.3 mm 4.30 · 67.4%4.5 mm 4.50 · 48.1%4.6 mm 4.604.13
    M6x1 5.00 (77%)5.0 mm 5.00 · 77%5.2 mm 5.20 · 61.6%5.4 mm 5.40 · 46.2%5.6 mm 5.604.92
    M7x1 6.00 (77%)6.0 mm 6.00 · 77%6.2 mm 6.20 · 61.6%6.4 mm 6.40 · 46.2%6.6 mm 6.605.92
    M8x1.25 6.80 (73.9%)6.8 mm 6.80 · 73.9%6.9 mm 6.90 · 67.7%7.2 mm 7.20 · 49.3%7.4 mm 7.406.65
    M10x1.5 8.50 (77%)8.5 mm 8.50 · 77%8.7 mm 8.70 · 66.7%9.0 mm 9.00 · 51.3%9.3 mm 9.308.38
    M12x1.75 10.20 (79.2%)10.3 mm 10.30 · 74.8%10.5 mm 10.50 · 66%10.9 mm 10.90 · 48.4%11.2 mm 11.2010.11
    M14x2 12.00 (77%)12.1 mm 12.10 · 73.1%12.3 mm 12.30 · 65.4%12.7 mm 12.70 · 50%13.1 mm 13.1011.84
    M16x2 14.00 (77%)14.0 mm 14.00 · 77%14.25 mm 14.25 · 67.4%14.75 mm 14.75 · 48.1%15.0 mm 15.0013.84
    M18x2.5 15.50 (77%)15.5 mm 15.50 · 77%16.0 mm 16.00 · 61.6%16.5 mm 16.50 · 46.2%17.0 mm 17.0015.29
    M20x2.5 17.50 (77%)17.5 mm 17.50 · 77%18.0 mm 18.00 · 61.6%18.5 mm 18.50 · 46.2%19.0 mm 19.0017.29
    M22x2.5 19.50 (77%)19.5 mm 19.50 · 77%20.0 mm 20.00 · 61.6%20.5 mm 20.50 · 46.2%21.0 mm 21.0019.29
    M24x3 21.00 (77%)21.0 mm 21.00 · 77%21.5 mm 21.50 · 64.2%22.0 mm 22.00 · 51.3%22.75 mm 22.7520.75
    M27x3 24.00 (77%)24.0 mm 24.00 · 77%24.5 mm 24.50 · 64.2%25.0 mm 25.00 · 51.3%25.75 mm 25.7523.75
    M30x3.5 26.50 (77%)26.5 mm 26.50 · 77%27.0 mm 27.00 · 66%27.75 mm 27.75 · 49.5%28.5 mm 28.5026.21
    M33x3.5 29.50 (77%)29.5 mm 29.50 · 77%30.0 mm 30.00 · 66%30.75 mm 30.75 · 49.5%31.5 mm 31.5029.21
    M36x4 32.00 (77%)32.0 mm 32.00 · 77%32.5 mm 32.50 · 67.4%33.5 mm 33.50 · 48.1%34.0 mm 34.0031.67
    M39x4 35.00 (77%)35.0 mm 35.00 · 77%35.5 mm 35.50 · 67.4%36.5 mm 36.50 · 48.1%37.0 mm 37.0034.67
    M42x4.5 37.50 (77%)37.5 mm 37.50 · 77%38.0 mm 38.00 · 68.4%39.0 mm 39.00 · 51.3%40.0 mm 40.0037.13
    M45x4.5 40.50 (77%)40.5 mm 40.50 · 77%41.0 mm 41.00 · 68.4%42.0 mm 42.00 · 51.3%43.0 mm 43.0040.13
    M48x5 43.00 (77%)43.0 mm 43.00 · 77%44.0 mm 44.00 · 61.6%45.0 mm 45.00 · 46.2%46.0 mm 46.0042.59
    M52x5 47.00 (77%)47.0 mm 47.00 · 77%48.0 mm 48.00 · 61.6%49.0 mm 49.00 · 46.2%50.0 mm 50.0046.59
    M56x5.5 50.50 (77%)50.5 mm 50.50 · 77%51.5 mm 51.50 · 63%52.5 mm 52.50 · 49%53.5 mm 53.5050.05
    M60x5.5 54.50 (77%)54.5 mm 54.50 · 77%55.5 mm 55.50 · 63%56.5 mm 56.50 · 49%57.5 mm 57.5054.05
    M64x6 58.00 (77%)58.0 mm 58.00 · 77%59.0 mm 59.00 · 64.2%60.0 mm 60.00 · 51.3%60.0 mm 60.0057.51
    ISO metric fine tap drills
    ThreadStandard drill (mm)75% drill65% drill50% drillForm tap (65%)Minor dia (mm)
    M3x0.35 fine2.65 (77%)2.65 mm 2.65 · 77%2.7 mm 2.70 · 66%2.75 mm 2.75 · 55%2.85 mm 2.852.62
    M4x0.5 fine3.50 (77%)3.5 mm 3.50 · 77%3.6 mm 3.60 · 61.6%3.7 mm 3.70 · 46.2%3.8 mm 3.803.46
    M5x0.5 fine4.50 (77%)4.5 mm 4.50 · 77%4.6 mm 4.60 · 61.6%4.7 mm 4.70 · 46.2%4.8 mm 4.804.46
    M6x0.75 fine5.25 (77%)5.3 mm 5.30 · 71.9%5.4 mm 5.40 · 61.6%5.5 mm 5.50 · 51.3%5.7 mm 5.705.19
    M8x1 fine7.00 (77%)7.0 mm 7.00 · 77%7.2 mm 7.20 · 61.6%7.4 mm 7.40 · 46.2%7.6 mm 7.606.92
    M10x1 fine9.00 (77%)9.0 mm 9.00 · 77%9.2 mm 9.20 · 61.6%9.4 mm 9.40 · 46.2%9.6 mm 9.608.92
    M10x1.25 fine8.80 (73.9%)8.8 mm 8.80 · 73.9%8.9 mm 8.90 · 67.7%9.2 mm 9.20 · 49.3%9.4 mm 9.408.65
    M12x1.25 fine10.80 (73.9%)10.8 mm 10.80 · 73.9%10.9 mm 10.90 · 67.7%11.2 mm 11.20 · 49.3%11.4 mm 11.4010.65
    M12x1.5 fine10.50 (77%)10.5 mm 10.50 · 77%10.7 mm 10.70 · 66.7%11.0 mm 11.00 · 51.3%11.3 mm 11.3010.38
    M14x1.5 fine12.50 (77%)12.5 mm 12.50 · 77%12.7 mm 12.70 · 66.7%13.0 mm 13.00 · 51.3%13.3 mm 13.3012.38
    M16x1.5 fine14.50 (77%)14.5 mm 14.50 · 77%14.75 mm 14.75 · 64.2%15.0 mm 15.00 · 51.3%15.25 mm 15.2514.38
    M18x1.5 fine16.50 (77%)16.5 mm 16.50 · 77%16.75 mm 16.75 · 64.2%17.0 mm 17.00 · 51.3%17.25 mm 17.2516.38
    M20x1.5 fine18.50 (77%)18.5 mm 18.50 · 77%18.75 mm 18.75 · 64.2%19.0 mm 19.00 · 51.3%19.25 mm 19.2518.38
    M20x2 fine18.00 (77%)18.0 mm 18.00 · 77%18.25 mm 18.25 · 67.4%18.75 mm 18.75 · 48.1%19.0 mm 19.0017.84
    M22x1.5 fine20.50 (77%)20.5 mm 20.50 · 77%20.75 mm 20.75 · 64.2%21.0 mm 21.00 · 51.3%21.25 mm 21.2520.38
    M24x2 fine22.00 (77%)22.0 mm 22.00 · 77%22.25 mm 22.25 · 67.4%22.75 mm 22.75 · 48.1%23.0 mm 23.0021.84
    M27x2 fine25.00 (77%)25.0 mm 25.00 · 77%25.25 mm 25.25 · 67.4%25.75 mm 25.75 · 48.1%26.0 mm 26.0024.84
    M30x2 fine28.00 (77%)28.0 mm 28.00 · 77%28.25 mm 28.25 · 67.4%28.75 mm 28.75 · 48.1%29.0 mm 29.0027.84
    M33x2 fine31.00 (77%)31.0 mm 31.00 · 77%31.25 mm 31.25 · 67.4%31.75 mm 31.75 · 48.1%32.0 mm 32.0030.84
    M36x3 fine33.00 (77%)33.0 mm 33.00 · 77%33.5 mm 33.50 · 64.2%34.0 mm 34.00 · 51.3%34.5 mm 34.5032.75
    M36x2 fine34.00 (77%)34.0 mm 34.00 · 77%34.5 mm 34.50 · 57.7%34.5 mm 34.50 · 57.7%35.0 mm 35.0033.84
    M39x3 fine36.00 (77%)36.0 mm 36.00 · 77%36.5 mm 36.50 · 64.2%37.0 mm 37.00 · 51.3%37.5 mm 37.5035.75
    M42x3 fine39.00 (77%)39.0 mm 39.00 · 77%39.5 mm 39.50 · 64.2%40.0 mm 40.00 · 51.3%40.5 mm 40.5038.75
    M42x2 fine40.00 (77%)40.0 mm 40.00 · 77%40.5 mm 40.50 · 57.7%40.5 mm 40.50 · 57.7%41.0 mm 41.0039.84
    M45x3 fine42.00 (77%)42.0 mm 42.00 · 77%42.5 mm 42.50 · 64.2%43.0 mm 43.00 · 51.3%43.5 mm 43.5041.75
    M48x3 fine45.00 (77%)45.0 mm 45.00 · 77%45.5 mm 45.50 · 64.2%46.0 mm 46.00 · 51.3%46.5 mm 46.5044.75
    M48x2 fine46.00 (77%)46.0 mm 46.00 · 77%46.5 mm 46.50 · 57.7%46.5 mm 46.50 · 57.7%47.0 mm 47.0045.84
    M52x3 fine49.00 (77%)49.0 mm 49.00 · 77%49.5 mm 49.50 · 64.2%50.0 mm 50.00 · 51.3%50.5 mm 50.5048.75
    M56x4 fine52.00 (77%)52.0 mm 52.00 · 77%52.5 mm 52.50 · 67.4%53.5 mm 53.50 · 48.1%54.0 mm 54.0051.67
    M56x2 fine54.00 (77%)54.0 mm 54.00 · 77%54.5 mm 54.50 · 57.7%54.5 mm 54.50 · 57.7%55.0 mm 55.0053.84
    M60x4 fine56.00 (77%)56.0 mm 56.00 · 77%56.5 mm 56.50 · 67.4%57.5 mm 57.50 · 48.1%58.0 mm 58.0055.67
    M64x4 fine60.00 (77%)60.0 mm 60.00 · 77%60.0 mm 60.00 · 77%60.0 mm 60.00 · 77%60.0 mm 60.0059.67
    M64x3 fine61.00 (77%)60.0 mm 60.00 · 102.6%60.0 mm 60.00 · 102.6%60.0 mm 60.00 · 102.6%60.0 mm 60.0060.75

    Common questions

    What is the metric tap drill formula?
    Tap drill ≈ major diameter − pitch. M10×1.5 → 8.5 mm, M12×1.75 → 10.2 mm (about 77–79% thread).
    What drill for M8×1.0 fine?
    7.0 mm.
    What drill for an M6 form tap?
    About 5.55–5.6 mm at 65% thread; follow the tap maker's table.

    Calculators that use this data

    Thread Percentage CalculatorPercent of thread from any drill for cut and form taps, with 75%, 65% and 50% tap drills.Tap Drill ChartRecommended tap drill sizes for UNC, UNF, and metric threads.Drill Chart & Size FinderFractional, number, letter and metric drills with decimal equivalents and a nearest-drill finder.

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