ARP Pro Series cylinder head studs are cold-forged to ensure molecular integrity. They’re heat-treated prior to thread rolling and machining. ARP Pro Series kits are also available with 12-point nuts, and all studs come complete with hardened parallel washers for an even load distribution and accurate torque readings. Fastener Material: 8740 Chromoly. Just Racing is an Engine Machine Shop and Retail Performance Parts Store based out of Las Vegas, NV. We are a full-service shop capable of building custom engines to fit the customer’s needs while providing quality parts at a great price! Your one stop shop for quality performance parts!