BARREL NUT,FLAT KNURLED NUT 1.ISO,ANSI,JIS,DIN,BS& non-standard fastener ... Grade:4.8 ,6.8,8.8,9.8.. BARREL NUT,FLAT KNURLED NUT,BARREL NUTS AND BOLTS . A good non-standard fastenerS ... steel is SS201,202,302,304,316...copper is shiny brass , pure copper,such as H62,H65,H68...Aluminum is ... manufacturer with more than 20 years experiences in screw,bolt,nut,washer,rivet, stud, pin,wrench and so on .2. ...