5-Pack Bolt Kit, Hex Head Black Oxide 652-1000 AR652-1000 3/8" UNC x 1.000" UHL With 3/8" Socket Head HEX BOLTS 3/8" UNC x 1.00" Now you can use premium quality ARP stainless steel or chrome moly fasteners to install most anything on a car, boat or trailer. ARP's specially alloyed stainless steel bolts and heat-treated 8740 chrome moly bolts with black oxide finish are nominally rated at 180,000 psi tensile strength to provide a substantial extra margin of safety over Grade 8 hardware. What's more, you can't beat the gorgeous looks of ARP's specially polished stainless steel fasteners, and their ability to resist rust. They're truly maintenance free!. Stainless Steel & Chrome Moly Bolts Available in Standard Sizes From #10 to 1/2? and Metric Sizes From M6 to M12 With Underhead Lengths Ranging From 1/2? to 6?. Hex or 12-Pt. Heads. Packaged In Convenient 5-Pack Cards.