When building your engine, you don't want to skimp on something that can potentially bite you in the butt later down the road. Do it right the first time and you won't have to worry about a second time. Their fasteners are made from 8740 Chrome Moly Steel for the highest level of strength and durability. The bolts are made from large coils of the raw material. They are heat treated and shot peened shortly afterwards. They are then thread rolled after the heat treating process which increases the fatigue strength significantly compared to being thread rolled before heat treatment. Everything done with ARP is done in house by their own employees to ensure only the best in quality control. There is no middle man, just ARP and their quality fasteners.
Best of all, the Austenitic stainless material is immune to rust, corrosion and hydrogen embrittlement when submersed in a water jacket or coolant based environment.
Optimum design, enhanced reliability, and increased strength are the main attributes of ARP's Pro Fastener Series fastener kits.