Now you can use premium-quality ARP chromoly bolts to install most anything on a car, boat, or trailer. These specially heat-treated 8740 chromoly fasteners feature a black oxide finish. They're nominally rated at 180,000 psi tensile strength to provide a substantial extra margin of safety over Grade 8 hardware. The bolts are available in a wide range of thread sizes, head styles, and other options. Bolts, 12-Point Head, Custom 450, Black Oxide, 1/4 in.-20 RH Thread, 0.515 in. UHL, Set of 5 Fastener Type: Bolt Thread Size: 1/4 in.-20 Fastener Head Style: Flanged 12-point Underhead Length (in.): 0.515 in. Brand: ARPPart Number: 640-0515.