M20 Tap Drill Size

Use a 17.5 mm drill for a M20 x 2.5 tap — .6890" (17.50 mm).

Rule of thumb for metric: drill = major diameter - pitch. For M20 that lands on 17.5 mm.

Nearby taps

Tap	Drill	Decimal
M16 x 2.0	14.0	.5512

Printable PDF version - Tap Drill Chart
Clean letter-size sheet for the toolbox or shop wall. Instant download, $3.49.