ISO Metric Coarse Thread · DIN 13-1 / ISO 261
M1.8 Thread: Pitch, Tap Drill & Dimensions
M1.8 is an ISO metric coarse thread with a 0.35 mm pitch. The tap drill is 1.45 mm, and the internal minor diameter D1 is 1.421 mm.
| Nominal (major) diameter | 1.8 mm |
|---|---|
| Pitch | 0.35 mm (coarse) |
| Tap drill (D − P) | 1.45 mm |
| Pitch diameter d2 / D2 | 1.573 mm |
| Minor diameter, external d3 | 1.371 mm |
| Minor diameter, internal D1 | 1.421 mm |
| Thread depth, external h3 | 0.215 mm |
| Flank angle | 60° |
Common questions
What size drill do I use to tap M1.8?
Use a 1.45 mm drill. This is the standard tap drill for M1.8; for hard materials or deep threads a slightly larger drill reduces tapping torque.
What is the pitch of M1.8?
The pitch of M1.8 is 0.35 mm (coarse), meaning the thread advances that distance in one full turn.
Where can I find other ISO Metric Coarse Thread sizes?
The full ISO Metric Coarse Thread 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.