... ,etc 3.Standard:ISO,DIN,ASME,etc Grade 4.6 Bolt And Nut sizeM3-M76Faceplain,zinc plated,black oxide,hot dip ... static sealing element of pipe ,value.pump,thermal exchange,condensing tower,plain hole and man hole of flange ,etcSpecial design available ... wooden cases or according to customers' requirements . Grade 4.6 Bolt And Nut