... 8.8,9.8........ WAVE PLATE HEAD SCREW,DOUBLE HEAD SCREW,KNURLED HEAD SCREW A good non-standard fastenerS ... for Machine threads.Head typesHexagon head,Mushroom head,Pan head,Countersunk head,Bugle head,Oval head,Hex flange head,Round head,Ball head,Button head...Socket typesPhillip type ... manufacturer with more than 20 years experiences in screw,bolt,nut,washer,rivet, stud, pin,wrench and so ...