Set Screws are commonly used to secure an object within or against another object, such as securing a pulley or gear to a shaft. These set screws are Headless Screws which are commonly called Blind Screws or Grub Screws. These headless screws comes with a Hex Socket in which a Hex Allen Wrench is inserted for tightening and loosening of the screw. Set screws are also used in applications where a flat surface is important, such as handles, grips, surfboard fins, and furniture or machine assembly.