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 traditional style hex nuts are manufactured from the finest aerospace-quality steel, rated at 180,000 psi tensile strength, and have a black oxide finish. Each package contains ten nuts with a socket size of 9/16 and a thread size of 3/8 - 24.