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M4 set / grub screw size
2 mm Allen key
hex key size for M4 set screw
M4 set screw — Shaft collars, pulleys, gears.
Full specification
| System | Metric coarse |
| Nominal diameter | 4 mm |
| Thread pitch | 0.7 mm |
| Allen key / hex socket | 2 mm |
| Tap drill | 3.3 mm |
| Clearance hole | 4.5 mm |
| Common grade / class | 12.9 |
| Typical torque | 2.5 Nm (1.84 ft·lb) |
About M4 set screws
Shaft collars, pulleys, gears.
Set screws (also called grub screws) are headless screws with a hexagonal socket. They are used to secure an object within or against another object. Common applications include securing pulleys, gears, and collars to shafts.
Grade 12.9 indicates high-strength alloy steel for demanding applications.
Frequently asked questions
- What size Allen key fits M4 set screw?
- M4 set screw uses a 2 mm Allen key.
- What is the torque for M4 set screw?
- Typical torque for M4 set screw in 12.9 is about 2.5 Nm (1.84 ft·lb).
- What are set screws used for?
- M4 set screws are used in shaft collars, pulleys, gears.