This page covers M6 Socket Head Cap Screw to GB/T 70.1 / ISO 4762: the full dimensional row, hole and tool sizes, proof-load data and typical applications. All values are taken from the governing standards (GB/T 70.1 / ISO 4762 together with ISO 273, ISO 724 and ISO 898-1 where applicable).
M6 Dimensional Row (GB/T 70.1 / ISO 4762)
| Size | Pitch (mm) | Length L (mm) | Head diameter dk (mm) | Head height k (mm) | Hex socket s (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M6 | 1.0 | 40 | 10.0 | 6 | 5.0 | ISO 4762 / GB/T 70.1 |
Spanner & Drive for M6 Socket Head Cap Screw — GB/T 70.1 / ISO 4762 (Series 014)
The hex socket for M6 Socket Head Cap Screw — GB/T 70.1 / ISO 4762 (Series 014) is shown in the spec table — use the matching Allen / hex key (an ISO 2936 hex key set covers the full range). A T-handle Allen key gives the best feel for setting preload by feel; for production work use a torque-controlled driver.
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 Socket Head Cap Screw — GB/T 70.1 / ISO 4762 (Series 014) Weight
A steel M6 socket head cap screw at the listed 40 mm length weighs approximately 25 g each — about 25 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 Socket Head Cap Screw — GB/T 70.1 / ISO 4762 (Series 014)
M6 Socket Head Cap Screw — GB/T 70.1 / ISO 4762 (Series 014) are commonly specified for machine assembly, general engineering, plant maintenance and OEM equipment.
Installation Tips for M6 Socket Head Cap Screw — GB/T 70.1 / ISO 4762 (Series 014)
- Use a quality Allen key fully seated in the socket — partial engagement is the most common cause of stripped sockets at this size.
- For countersunk and button-head variants, chamfer the through-hole to seat the head flush without preloading the head/shank fillet.
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.