flat washer size :m3--m64 material :Carbon Steel, Alloy Steel, Stainless Steel flat washersize :m4--m64material :Carbon Steel, Alloy Steel, Stainless Steel, Copper, Nylon, Plastic, etccoating ... , nylon insert lock nuts, cap nuts, slotted nuts, rivet nutWASHERS: flat washers, spring washers, lock washersSCREWS: machine screws, self tapping screws ...