On the bench specifying M12 Hex Socket Cone Point Set Screw — GB/T 77 / ISO 4026 (Series 022)? This page gives the controlling dimensions for the M12 size of Hex Socket Cone Point Set Screw — GB/T 77 / ISO 4026 (Series 022) (to GB/T 77 / ISO 4026).
M12 Dimensional Row (GB/T 77 / ISO 4026)
| Size | Pitch (mm) | Length L (mm) | Hex socket s (mm) | Engagement depth t min (mm) | Point diameter dp (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M12 | 1.75 | 18 | 6.0 | 6.0 | 8.5 | ISO 4026-4029 / GB/T 77-79 |
Spanner & Drive for M12 Hex Socket Cone Point Set Screw — GB/T 77 / ISO 4026 (Series 022)
The hex socket for M12 Hex Socket Cone Point Set Screw — GB/T 77 / ISO 4026 (Series 022) 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 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 Hex Socket Cone Point Set Screw — GB/T 77 / ISO 4026 (Series 022)
M12 Hex Socket Cone Point Set Screw — GB/T 77 / ISO 4026 (Series 022) are commonly specified for heavier machine assembly and equipment mounting.
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.