ARP-Audi RS3/TT-RS (DAZA/DWNA) CA625+ Head Stud Kit

ARP CA625 is a high-strength, super-alloy head stud material used to secure cylinder heads to engine blocks.
CA625+®️: This super-alloy demonstrates superior fatigue 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+. Typical tensile strength is 260,000-280,000 psi.

There is no other material on the market better suited for cylinder head clamping. 625+ material is substantially stronger than any entry level 8740 head stud material, and substantially stronger than L19.

Features :
Tensile strength: CA625 has a minimum tensile strength of 260,000 psi
Fatigue life: CA625 has a superior fatigue cycle life
Corrosion resistance: CA625 is resistant to atmospheric corrosion and oxidation
Heat treatment: CA625 is heat-treated to ensure molecular integrity
Centerless ground: CA625 is centerless ground to ensure perfect concentricity
Broached ends: CA625 has broached ends for easy installation

Why use ARP CA625?
ARP CA625 is used to provide the clamping force required to keep cylinder heads from lifting due to high combustion pressures. It's also used to replace factory fasteners that are not designed for performance use.