On the bench specifying M3 Slotted Long Dog Point Set Screw — GB/T 75 / ISO 7435 (Series 041)? This page gives the controlling dimensions for the M3 size of Slotted Long Dog Point Set Screw — GB/T 75 / ISO 7435 (Series 041) (to GB/T 75 / ISO 7435).
M3 Dimensional Row (GB/T 75 / ISO 7435)
| Size | Pitch (mm) | Length L (mm) | Hex socket s (mm) | Engagement depth t min (mm) | Point diameter dp (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M3 | 0.5 | 6 | 1.5 | 1.4 | 2.0 | ISO 4026-4029 / GB/T 77-79 |
Spanner & Drive for M3 Slotted Long Dog Point Set Screw — GB/T 75 / ISO 7435 (Series 041)
The hex socket for M3 Slotted Long Dog Point Set Screw — GB/T 75 / ISO 7435 (Series 041) 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 M3
| Coarse-thread pitch (ISO 724) | 0.5 mm |
|---|---|
| Through-hole / clearance (ISO 273 medium) | 3.4 mm |
| Tapping drill, coarse thread | 2.5 mm |
Tightening Torque for M3
| Class 8.8 (dry, ~µ 0.125) | ≈ 1.3 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 1.8 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 2.1 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 M3 Slotted Long Dog Point Set Screw — GB/T 75 / ISO 7435 (Series 041)
M3 Slotted Long Dog Point Set Screw — GB/T 75 / ISO 7435 (Series 041) are commonly specified for electronics, PCB hardware, optical mounts and small-scale machinery.
Installation Tips for M3 Slotted Long Dog Point Set Screw — GB/T 75 / ISO 7435 (Series 041)
- 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.
- At M3 the joint is sensitive to over-torque — use a torque-limiting driver and check the head doesn't bury into a softer counterpart.
Mating Parts for M3
For M3, pair with a M3 hex nut (ISO 4032 / DIN 934) and, where used, a M3 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.