These ARP Speed Nuts are designed for professional racing environments where split-second improvements in pit stop times can make the winning difference. The 200,000 psi chromoly steel “unbustable” reliability of these ARP Speed Nuts can be seen in the manufacturing process and design. With socket release and resistance to jamming in mind, ARP uses the formed threading method and then double magnafluxes, heat-treats, and finally coats them with Alumotef III, which gives you the ultimate in Speed Nuts. These lug nuts are what we run on our own race trucks and recommend to use with our race hubs. These are for 5/8″-18 RH threads and have a 90 degree taper for race wheels. These do not work with OEM 60 degree tapers or flat seats. You need to check your wheel lug nut seats prior to ordering. A 1″ 6pt deep socket fits these.