ARP M12 x 1.25 & 1.50 x 5.275 ARP2000

In early 1970s, racing enthusiast Gary Holzapfel saw his friend break his engine due to failed bolts. At that time there were no better options for a private person. So Holzapfel took the plunge, used his many years of experience in the industry as a subcontractor to the aerospace industry and founded ARP (Automotive Racing Products).
Since then, ARP has grown from a garage in the back, to a leading manufacturer of components used worldwide over. Today, they have 7 premises with a combined area of nearly 19,000 square meters, where they handle forging, heat treatment, milling, quality control and packaging. 

ARP today has thousands of article numbers and is today a standard in engine construction. You don't talk about upgraded bolts anymore. You say that you have mounted ARP bolts.