M10 Metric Thread
Direct Answer
M10 is an ISO metric machine screw thread with a nominal major diameter of 10.0 mm and a standard coarse pitch of 1.50 mm. Requiring an 8.50 mm tap drill, it is standard in automotive engine mounts, suspension control arms, motorcycle rear-view mirrors, and commercial HVAC hanging brackets.
Source: ISO 68-1 / ISO 261 / DIN 13-1
Specs
| Nominal Major Diameter | 10.00 mm |
| Standard Coarse Pitch | 1.50 mm |
| Fine Pitch (Automotive Standard) | 1.25 / 1.00 mm |
| Tap Drill Diameter (Coarse) | 8.50 mm (75% thread engagement) |
| Minor Diameter (Internal) | 8.376 mm |
| Tensile Stress Area | 58.0 mm² |
| Common Drive Size | 17mm (ISO) / 16mm (DIN) / 15mm / 8.0mm Allen |
Automotive Coarse vs Fine Pitch (M10×1.25)
In general construction, M10 coarse pitch is 1.5 mm. In Japanese (JIS) and European automotive engineering, M10 fine pitch (M10×1.25 mm) is widely used on brake calipers, engine subframes, and suspension components to provide higher resistance to vibration-induced loosening.
Motorcycle Mirror Threading Conventions
Motorcycle handlebars universally use M10 threads for rear-view mirrors. While most manufacturers (Honda, Suzuki, Kawasaki) use standard right-hand (clockwise) M10 threads, Yamaha uses a left-hand (counter-clockwise / reverse) M10 thread on the right-side mirror to prevent wind resistance from unscrewing it.