... brass,copper Finish:Plain,black,zinc plated,nickle,etc Description:Internal teeth serrated lock washers Features:1)Standard:DIN,ISO,ANSI ... non standard2)Material:Steel,stainless steel,brass,copper3)All types and sizes are available,also produce according to customers'drawings ... and samples4)Finish:Plain,zinc plated,black,chromate,dacoramt,HDG, ...