ARP 2000 Head Stud Kit Ford Focus ST 2013-2018 | Focus RS 2016-2018Pro series cylinder head studs from ARP are cold forged to ensure molecular integrity. They are heat treated prior to thread rolling and machining and are rated at a whopping 220,000 psi. ARP Pro series kits are also available with 12 point nuts, and all kits come complete with hardened parallel washers for an even load distribution and accurate torque readings.