To maintain a reputation for "zero defects", ensure optimum quality control, and produce fasteners of exceptionally high quality, ARP controls all aspects of the manufacturing process, performing all operations in-house where they can be closely monitored. ARP takes extraordinary steps to produce the very finest products of their kind on the market today. These compact 12-point style nuts are manufactured from the finest aerospace-quality polished stainless steel, and are rated at 180,000 psi tensile strength. Each package contains ten nuts with a socket size of 5/16 and a thread size of 1/4 - 28.