ARP - Custom Age 625+ Head Studs - WRX/STi EJ2.0/2.5L

This newly formulated super-alloy demonstrates superior fatigue cycle life, tensile strength and toughness – with complete resistance to atmospheric corrosion and oxidation. ARP is the first to develop manufacturing and testing processes for fasteners with Custom Age 625+. Best of all it is less expensive and expected to soon replace MP-35 as the material of choice in the high strength, super-alloy field. Typical tensile strength is 260,000-280,000 psi.

All Custom Age 625+ studs are centerless ground, heat treated prior to thread rolling and machining, and ar nominally rated at 270,000 psi. These fasteners deliver a 55% increase in tensile strength and are reusable as compared to the OEM Torque to Yield (TTY) head bolts.

In the box:
12 X Set of Custom Age 625+ Head Studs - 11mm
12 X Parallel Ground Washers
12 X Chrome Moly Steel 12 Point Nuts
1 X 1/2oz pack of ARP Ultra-Torque fastener assembly lubricant