M6 identifies the nominal diameter, but the pitch completes the callout. This page covers the common M6 × 1.0 coarse thread, not every M6 pitch.
Calculation cross-check
The simple metric cut-tap estimate is nominal diameter minus pitch: 6.0 mm − 1.0 mm = 5.0 mm. Here it agrees with the reviewed maker recommendation.
Confirm the pitch
An M6 fastener can be encountered with another pitch. Use a pitch gauge or a known mating part and record the complete M6 × pitch callout.
Important limitation
Forming taps require a different hole. Do not substitute the 5.0 mm cut-tap value.
Forming taps require a different hole. Do not substitute the 5.0 mm cut-tap value.
Technical references
- Cle-Line C01112 Tap and Drill Recommendations — Greenfield Industries / Cle-Line. Accessed 2026-11-09.
- Tapping Sizes and Clearance Holes — TR Fastenings. Accessed 2026-11-10.
Standards references identify scope and terminology; protected dimensional tables are not reproduced.