WAVE PLATE HEAD SCREW 1.ISO,ANSI,JIS,DIN,BS& non- ... 3.Grade:4.8 ,6.8,8.8,9.8........ WAVE PLATE HEAD SCREW,DOUBLE HEAD SCREW,KNURLED HEAD SCREW A ... is SS201,202,302,304,316...copper is shiny brass , pure copper,such as H62,H65,H68...Aluminum is good Aluminum ...