M12 Metric Thread
Direct Answer
M12 is an ISO metric machine screw thread with a nominal major diameter of 12.0 mm and a standard coarse pitch of 1.75 mm. Requiring a 10.20 mm tap drill, it provides high tensile clamping strength for automotive wheel hubs, structural steel connections, and industrial machine tool mounts.
Source: ISO 68-1 / ISO 261 / DIN 13-1 / ISO 898-1
Specs
| Nominal Major Diameter | 12.00 mm |
| Standard Coarse Pitch | 1.75 mm |
| Fine Pitch (Automotive) | 1.50 / 1.25 mm |
| Tap Drill Diameter (Coarse) | 10.20 mm (75% thread engagement) |
| Minor Diameter (Internal) | 10.106 mm |
| Tensile Stress Area | 84.3 mm² |
| Common Drive Size | 19mm (ISO) / 18mm (DIN) / 10.0mm Allen |
Automotive Wheel Lug Fastening (M12×1.5 / M12×1.25)
M12 fine threads are the global standard for wheel lug nuts and wheel studs on compact and mid-size passenger cars. Toyota, Honda, Ford, and GM primarily use M12×1.5 mm, while Nissan and Subaru specify M12×1.25 mm. Attempting to interchange these fine pitch nuts will instantly destroy the wheel stud threads.
High-Strength Structural Bolting
In Class 8.8 and Class 10.9 high-tensile steel grades (ISO 898-1), a single M12 bolt has a proof load capacity exceeding 50 to 70 kN (~11,000 to 15,700 lbf), making it the entry standard for structural construction anchor brackets and heavy machinery bases.