ARP only uses premium grade 8740 alloy and a proprietary ARP2000 alloy that are rated for superior to "aircraft" quality alloy steels. Secondly, each stud is placed vertically into special racks and precisely heat-treated to 200,000 psi for the 8740 material and 220,000 psi for the ARP2000 material. This procedure ensures complete heat penetration and the results are far superior to those lesser quality studs from other manufacturers who just dump pieces in a basket and hope for the best.

Product Features:

• 12mm 12-Point, 4mm Allen Socket Size(s)
• ARP2000
• Black Oxide
• BMW 2.5L, 3.0L, 3.2L
• Sold As A Kit