Torx® Tamper-Resistant Cap Screws manufactured from 18-8 stainless steel, incorporate a solid post formed in the center of the recess during the heading process. These fasteners are extremely difficult to remove without a special tamper-resistant tool. The Torx® Tamper-Resistant Drive System is recognized as one of the most efficient fastening systems because of its ability to transfer greater torque, reduce load and virtually eliminate tool slippage.