UNC/UNF ANSI B18.3, Steel self colour/Zinc plated

These High Tensile socket countersunk screws are made out of 10.9 steel material with a self colour black finish to ANSI B18.3 with an American unified coarse thread.  Measured from end to end.  They are also known as FHSC (Flat head socket caps) or SKT CSK.  The screw is designed to be seated into a countersunk hole, providing a flush finish.  A hex key ( sometimes referred to as an Allen wrench of Allen key) or hex driver is required to tighten or loosen a socket screw. Socket screws are commonly used in assemblies that do not provide sufficient clearance for a conventional wrench or spanner.  Please note that not all socket countersunk screws are fully threaded, if thread length is critical please contact us for more info.