L.H. Dottie HNS516 5/16''-18 Stainless Steel Hex Nut. Stainless Steel Hex Nuts are manufactured from 18-8/304 stainless steel and are used to connect both metal and wood components. They are also used in conjunction with stainless steel bolts, screws, studs, threaded rod and any other stainless steel fastener that has machine screw threads. Stainless Steel Hex Nuts are covered under the ASME B18.2.2-2015 and ASME B1.1 - 2003 standard.