Metric, ISO 7380-1, Zinc Plated

These Torx button screws are made out of 10.9 steel material with a bright zinc plate to ISO 7380 and have a metric coarse thread.  They are sometimes known as star or hexalobular round head or dome head Screws, and characterized by the 6 point star shaped pattern. They have a Torx recessed drive.  A Torx key ( sometimes referred to as an Torx wrench) or Torx driver is required to tighten or loosen a torx screw. Torx screws are commonly used in assemblies that do not provide sufficient clearance for a conventional wrench or spanner and the torx design allows for a higher torque to be used than a similary sized conventional socket drive screw and prevent Cam out.  These low profile rounded head screws are often used for their aesthetic qualities.