We can supply this kind of product according to standards and customer's requirements. 1.Standards:DIN ,ANSI/ASME,BS,GB,JIS,Non-standard2.Metail:Carbon steel,stainless steel,alloy steel..3.class:4.8,8.8,10.9,12.9.etc4.Surface:plain,zinc plated,black oxide,hot dip galv.etc.