... brass,alloy steel 3.surface treatment: zinc plate,balck,blue,plain. Name: machining nuts,hex nutMaterial:carbon steel,SS,brass,alloy ... steel,aluminium,etcSurface treatment: zinc plate,balck,blue,plain.Clients' drawing and samples is welcome.we have cutting maching,CNC machine ... ,drilling machine,lathe machine,and others to produce all kinds of nuts,material also ...