Now you can use premium quality ARP fasteners to install most anything on a car, boat, or trailer. You can't beat the gorgeous looks of the specially polished stainless steel bolts, and their ability to resist rust. They're truly maintenance free. Nominally rated at 170,000 psi tensile strength, this hardware provides a substantial extra margin of safety over Grade 8 hardware, and the bolts are conveniently packaged five to a card. These bolts feature a traditional hex style head, have a diameter of 5/16", a standard thread pitch of 18, an under head length of 0.560, and the wrenching is 3/8.