ISO 965-1 UNDERSTANDING THREAD CALLOUTS ON DRAWINGS BASIC FORMAT M [Diameter] × [Pitch] – [Tolerance Class] – [Options] Example: M10 × 1.5 – 6H/6g – L SYMBOL MEANINGS Symbol Meaning Example M Metric thread M (always first) Number (first) Nominal diameter in mm M10 = 10mm diameter × Number Pitch in mm (distance between threads) … Continue reading Metric Thread Designation – Quick Guide for Drawings