Allen Socket Blind Grub Set Screw Insert Nut

Hex Socket Set Screws or “Flat Head” Screws with Allen Drives for Metric Sizes.

Metric Hex Socket Set Screws are manufactured in grade A2 stainless steel. A stainless steel hex socket set screw is a type of screw that is typically used to secure one object within or against another object. The most common example is securing a pulley or gear to a shaft. Set screws are usually headless, also known as blind screws. This means that the screw is fully threaded, with no head protruding beyond the large diameter of the thread.

Blind set screws (called grub screws in the UK, probably because of their resemblance to a grub in the soil) are almost always driven with an internal wrench, such as a hex socket (allen) set screw that passes through a threaded hole in an external object and is tightened against an internal object to prevent it from moving relative to the external object. It applies a compressive or clamping force through the bottom tip that protrudes from the hole. Metric A2 stainless steel is corrosion and rust resistant.