Half -Cut Torx increases strength and improves fastener engagement All drivers with tamper-proof holes for security fasteners Half-Cut TORX drivers, also drive TORX Plus S2 steel, the strongest hardest drivers heat treated to 58-6 Satin Chrome plated driversThe Half-Cut Torx have the Torx Tip cut Shallower than normal Torx, this increases the strength, and makes fastener fit much tighter. This set includes the following: 12 piece Hal-Cut Torx stubby tamper proof security drivers, T8 - T60 and 10 piece 4 long Hal-Cut Torx tamper proof security drivers T8 - T50. All included in a durable plastic storage case and all have the limited lifetime warranty.