ISO Metric Fine Thread, pitch 1.5 · DIN 13-6

M20 × 1.5 Thread: Pitch, Tap Drill & Dimensions

M20 × 1.5 is an ISO metric fine thread with a 1.5 mm pitch. The tap drill is 18.5 mm, and the internal minor diameter D1 is 18.376 mm.

Profile shape (schematic, not to scale)
M20 × 1.5 thread dimensions
Nominal (major) diameter20 mm
Pitch1.5 mm (fine)
Tap drill (D − P)18.5 mm
Pitch diameter d2 / D219.026 mm
Minor diameter, external d318.16 mm
Minor diameter, internal D118.376 mm
Thread depth, external h30.92 mm
Flank angle60°
Clearance hole (fine / medium / coarse)21 / 22 / 24 mm

Common questions

What size drill do I use to tap M20 × 1.5?

Use a 18.5 mm drill. This is the standard tap drill for M20 × 1.5; for hard materials or deep threads a slightly larger drill reduces tapping torque.

What is the pitch of M20 × 1.5?

The pitch of M20 × 1.5 is 1.5 mm (fine), meaning the thread advances that distance in one full turn.

Where can I find other ISO Metric Fine Thread, pitch 1.5 sizes?

The full ISO Metric Fine Thread, pitch 1.5 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.

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