Selecting Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093), M12, in GB/T 901 / DIN 939: the dimensional row from the standard plus the tools and hole sizes follow. Use them with the technical drawing below — the drawing redraws to the exact size you pick.
M12 Dimensional Row (GB/T 901 / DIN 939)
| Thread size | Pitch (mm) | Length L (mm) | Engagement depth bm (mm) | Material | Reference standard |
|---|---|---|---|---|---|
| M12 | 1.75 | 100 | 18 | Cl. 8.8 alloy steel | DIN 939 / GB/T 901 |
Spanner & Drive for M12 Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093)
Drive geometry for M12 Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093) is given by the row above; match the tool to the listed values.
Hole Sizes for M12
| Coarse-thread pitch (ISO 724) | 1.75 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 13.5 mm |
| Tapping drill, coarse thread | 10.2 mm |
Tightening Torque for M12
| Class 8.8 (dry, ~µ 0.125) | ≈ 85 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 120 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 145 Nm |
Indicative dry-joint values. Lubrication can lower the required torque by 15–25%. Always confirm against the joint design, especially when going up a strength class.
Common Applications for M12 Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093)
M12 Equal-End Stud Bolt — GB/T 901 / DIN 939 (Series 093) are commonly specified for medium-duty structural connections, automotive sub-frames and equipment chassis.
Mating Parts for M12
For M12, pair with a M12 hex nut (ISO 4032 / DIN 934) and, where used, a M12 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
When to Step Up or Down from M12
When the joint preload approaches the proof load of M12 class 8.8, step up to M16 class 8.8 (or move to M12 class 10.9). When the joint is over-specified, M10 often saves weight and cost without losing the safety margin.