Grub Screw Socket Set Screw Metric Set Screws Lathe Finish Stainless

Grub screw is also known as set screw. A grub screw is a type of screw generally used to secure an object within or against another object, normally not using a nut (see bolts compared with screws). The most common examples are securing a pulley or gear to a shaft. Grub screws are usually headless (also called blind), meaning that the screw is fully threaded and has no head projecting past the major diameter of the screw thread. If a set screw has a head, the thread will extend all the way to the head (whereas a bolt might have an unthreaded shank between the head and thread). A blind grub screw is almost always driven with an internal-wrenching drive, such as a hex socket (Allen), star (Torx), square socket (Robertson), or slot. The grub screw passes through a threaded hole in the outer object and is tightened against the inner object to prevent it from moving relative to the outer object. It exerts compressional or clamping force through the bottom tip that projects through the hole. Ever Hardware provides custom-made fasteners and customizable packaging.
A potentiometer knob with a grub screw for locking it in place.
An example application is when a grub screw is screwed into a pulley hub so that its end-point bears firmly against the shaft. The fastening action is by friction between the screw and the shaft, often (but not always) with some amount of elastic or plastic deformation of one or both.