ISO Metric Fine Thread, pitch 1 and 1.25 · DIN 13-5
M20 × 1 Thread: Pitch, Tap Drill & Dimensions
M20 × 1 is an ISO metric fine thread with a 1 mm pitch. The tap drill is 19 mm, and the internal minor diameter D1 is 18.917 mm.
| Nominal (major) diameter | 20 mm |
|---|---|
| Pitch | 1 mm (fine) |
| Tap drill (D − P) | 19 mm |
| Pitch diameter d2 / D2 | 19.35 mm |
| Minor diameter, external d3 | 18.773 mm |
| Minor diameter, internal D1 | 18.917 mm |
| Thread depth, external h3 | 0.613 mm |
| Flank angle | 60° |
| Clearance hole (fine / medium / coarse) | 21 / 22 / 24 mm |
Common questions
What size drill do I use to tap M20 × 1?
Use a 19 mm drill. This is the standard tap drill for M20 × 1; for hard materials or deep threads a slightly larger drill reduces tapping torque.
What is the pitch of M20 × 1?
The pitch of M20 × 1 is 1 mm (fine), meaning the thread advances that distance in one full turn.
Where can I find other ISO Metric Fine Thread, pitch 1 and 1.25 sizes?
The full ISO Metric Fine Thread, pitch 1 and 1.25 table, with every size and a live filter, is on its standard page, and the Thread Finder searches all 73 standards at once.
Reference values; computed values use the ISO basic profile. Verify against the current standard before production use.