... ,white zinc,black oxideSize:M2-M22Min order:100,000pcsStasndard:JIS,DIN,ISO,ANSI,GB,BSPacking:carton box,paper bag,polyt bagtrade term ... . ) etc.Heat TreatmentTempering,Hardening,Spheroidizing,Stress Relieving.StandardISO,GB,DIN,JIS,ANSI,BSWManufacture ProcessHeading/washer assembly/Threading/Secondary machine/heat treatment/plating ...