Reinforced cylinder head studs ARP AUDI S4 RS4 B5 2.7T 30V AGB ASJ AZB AZR

This kit of reinforced cylinder head studs for AUDI S4/RS4 B5 is made up of 16 ARP studs and 16 ARP nuts.

Find the assembly instructions in the "Download" tab above.

Coming from the aerospace industry, Gary Holzapfel founded the brand ARP (Automotive Racing Products) in the early 1970s to address a major problem in motorsport: engine failure caused by screws and studs that weren't strong enough. At the time, no manufacturer was capable of meeting these needs. Today ARP offers thousands of references across different ranges and types of products such as head bolts, main bearing bolts and con rod bolts. Depending on the application, ARP offers different ranges (materials) of hardware:

• 8740: a chrome-molybdenum steel with standard strength properties fully suited to prepared engines. This steel offers a tensile strength of between 1240 and 1447 N/mm2.
• ARP2000: stronger than 8740, the ARP2000 alloy can withstand clamping / tensile loads of up to 1516 N/mm2. This range of studs is frequently used on track and drag cars and can be used with hydrogen.
• L19: a high quality treated steel offering significantly higher tensile and fatigue strength properties than the 8740 and ARP2000 ranges. Its tensile strength can reach up to 1792 N/mm2. This material is more sensitive to corrosion and must therefore be kept oiled and not exposed to moisture. Using hydrogen with this range is not recommended.
• CA625+ (Custom Age 625 Plus): this "super-alloy" has significantly superior technical properties while being resistant to corrosion and oxidation. Its tensile strength can reach 1930 N/mm2.

All ARP hardware is designed and manufactured in the United States. Manufacturing of ARP hardware begins with cold or hot forging, then a heat treatment (different depending on the range) is applied, followed by shot peening to eliminate irregularities. Precision grinding then follows to achieve perfect concentricity, before the thread is cut. Finally comes the finish, during which a coating such as black chrome-molybdenum oxide or stainless steel polishing is applied, depending on the product range.

Each kit is supplied with assembly lubricant and instructions indicating:

• Installation steps
• Thread of screws / studs / nuts
• Tightening torque
• Tightening procedure