In the world of high-quality engine fasteners, it doesn’t get much better than Automotive Racing Products, more commonly known as ARP. Despite having used them many times, we’ve never really thought about what goes into their manufacturing. Hagerty’s Brandan Gillogly took a tour of ARP’s Southern California facility recently and helped clarify how the company became one of the biggest names in performance engine building — namely quality and attention to detail.
The entire process starts with spools of chrome-moly and stainless steel wire, machined in-house to remove any defects from the manufacturing process. Then, a sample of each wire is sent to an independent lab for metallurgical testing.
From there, the bolts go onto the various forming processes. Generally, the bolt head is formed at room temperature, but sometimes ARP will heat the head with inductive heating to form special heads. After forming headed bolt blanks and semi-machined studs, everything is heat treated or aged, depending on the materials used in the bolt, before the threads are formed. Once the bolt is properly treated, ARP tumbles the bolts clean and then rolls on the threads.
We were curious about other aspects of the process that Hagerty might not have seen, and we found this great three-part mini-series that takes a broader approach to the entire process and shows how the bolts get thrown into boxes without any missing pieces.
Check out the video above, and click through to see Hagerty’s most recent tour.