Any screw used to hold or adjust a setting. Frequently a setscrew (1), but may also refer to any other machine screw or thumb screw used for the purpose of setting
(n) A mechanical threaded fastener, with or without a head, used to prevent rotation or movement between parts, such as a shaft and a collar Set screws have special types of points for different applications
A screw or bolt threaded into a ring or collar, designed to press against the shaft that the collar surrounds, so that the ring is held solidly against the shaft Rings with set screws are used to hold some cartridge bearing hubs and bottom bracket assemblies together Some tandem eccentric bottom brackets use set screws to hold the eccentric in position A very few (mostly antique) bicycles also use set screws to secure the seatpost in the frame