... steel (304,316) aluminium(5052,5056)Head type Flat head, small/reduced head, csk headBody type: round, knurled/ribbed, hexagon, blindSize :GB ... 8MaterialCarbon steel, stainless steel and aluminiumHeadFlat head,small head,countersunk head, flat hexagon headBodyRound,knurled,semi-hexagon,full-hexagon,UsageThe best way ... with the good quality and competitive price. rivet nut stainless steel; carbon nut