Hole sizes for the machine making the part
All sizes

Metric tap drill chart

Tap drill diameter for every metric thread in the catalog, M1.6-0.35 to M24-3.0, coarse and fine pitch. Need the hole a screw passes through instead? See the metric clearance hole chart. Tap any size for its full page: heat-set pockets, nut pockets, head recesses and 3D-printing numbers.

SizePitch (mm)Tap drill (mm)
M1.6-0.350.351.25
M2-0.40.41.6
M2.5-0.450.452.05
M3-0.50.52.5
M3.5-0.60.62.9
M4-0.70.73.3
M5-0.50.54.5
M5-0.80.84.2
M6-0.750.755.2
M6-1.015
M8-1.017
M8-1.251.256.8
M10-1.019
M10-1.251.258.8
M10-1.51.58.5
M12-1.251.2510.8
M12-1.51.510.5
M12-1.751.7510.2
M14-1.51.512.5
M14-2.0212
M16-1.51.514.5
M16-2.0214
M18-1.51.516.5
M18-2.52.515.5
M20-1.51.518.5
M20-2.52.517.5
M22-2.52.519.5
M24-2.0222
M24-3.0321
All values mm; tap drill highlighted. Pitch sets the tap drill. Clearance hole sizes are on the <a href="/charts/metric-clearance-holes/">metric clearance hole chart</a>.
These are standard reference numbers. Every machine prints and cuts a little differently - set a hole to Ø5.00 and it might land at Ø4.95. In the FitCheck app you calibrate your machine, and the clearance and pocket diameters here shift to match it - plus tolerance bands and full offline use.

Metric and imperial clearances follow published mechanical-engineering references · heat-set pockets per CNC Kitchen · bearing housing seats follow published fit tables. Reference only - verify before you cut.