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Machining / Threads
Tap Drill Calculator
Look up recommended tapping drills or estimate a metric drill from major diameter and pitch.
Thread standard
Recommended tap drill
M21.82 mm
5/64 in nearest fractional drill
- Nominal thread
- M2
- Pitch
- 0.4 mm
- Tap drill diameter
- 1.82 mm
- Nearest fraction
- 5/64 in
Reference values are preferred. The metric estimate uses major diameter minus pitch and should be checked against the tap manufacturer’s recommendation for the material and desired thread engagement.