... :M3-M22 3Bolt material:Carbon steel 4.Effect:Connection,Fastening Export carbon steel hex bolt and nut Products Details ... M3-M22 Standard NO.: DIN933,DIN931,DIN934 Material:: Carbon steel,stainless steel Grade: 4.8-12.9 Finish: zinc,black,chrome ... industry, food machinery, construction decoration, solar energy industry, water treatment equipment industry, electronic industry and other industries. • ...