1.name: machining nuts,hex nut 2.Material:carbon steel,SS,brass,alloy steel ... 3.surface treatment: zinc plate,balck,blue,plain. Name: machining nuts,hex nutMaterial:carbon steel,SS,brass,alloy steel,aluminium,etcSurface ... machine,lathe machine,and others to produce all kinds of nuts,material also with different metal. custom made all kinds ...