M6 Stud Bolt, Double-End are manufactured to GB/T 15389 / DIN 938 with a coarse thread pitch of 1 mm. This page lists the controlling dimensions for the M6 size — head geometry, width across flats, matching spanner size — together with the clearance hole, tapping drill and tightening torque used at assembly.
M6 Dimensional Row (GB/T 15389 / DIN 938)
| Thread size | Pitch (mm) | Length L (mm) | Engagement depth bm (mm) | Material | Reference standard |
|---|---|---|---|---|---|
| M6 | 1.0 | 50 | 8 | Cl. 8.8 alloy steel | DIN 939 / GB/T 901 |
Spanner & Drive for M6 Stud Bolt, Double-End — GB/T 15389 / DIN 938 (Series 092)
Drive geometry for M6 Stud Bolt, Double-End — GB/T 15389 / DIN 938 (Series 092) is given by the row above; match the tool to the listed values.
Hole Sizes for M6
| Coarse-thread pitch (ISO 724) | 1 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 6.6 mm |
| Tapping drill, coarse thread | 5 mm |
Tightening Torque for M6
| Class 8.8 (dry, ~µ 0.125) | ≈ 10 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 14 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 17 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.
Proof Load & Strength for M6
| Tensile stress area As (ISO 898-1) | 20.1 mm² |
|---|---|
| Proof load, class 8.8 | 12 kN |
| Proof load, class 10.9 | 17 kN |
| Proof load, class 12.9 | 19 kN |
| Min. ultimate tensile, class 8.8 | 16 kN |
Proof load = stress area × proof stress per ISO 898-1. Design joints so the working preload stays below the proof load of the selected class.
M6 Stud Bolt, Double-End — GB/T 15389 / DIN 938 (Series 092) Weight
A steel M6 stud bolt, double-end at the listed 50 mm length weighs approximately 11 g each — about 11 kg per 1,000 pieces. Stainless A2/A4 weighs roughly the same (density 7.9–8.0 g/cm³). Actual weight varies slightly with head form, thread and finish; use this figure for freight estimation only.
Common Applications for M6 Stud Bolt, Double-End — GB/T 15389 / DIN 938 (Series 092)
M6 Stud Bolt, Double-End — GB/T 15389 / DIN 938 (Series 092) are commonly specified for general-purpose machinery, jigs, fixturing and light structural connections.
Mating Parts for M6
For M6, pair with a M6 hex nut (ISO 4032 / DIN 934) and, where used, a M6 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
When to Step Up or Down from M6
When the joint preload approaches the proof load of M6 class 8.8, step up to M8 class 8.8 (or move to M6 class 10.9). When the joint is over-specified, M5 often saves weight and cost without losing the safety margin.

