Diaphragm coupling (Clamping screw ) 1.steel,stainless steel; aluminum 2.Steel,Black Oxide Finish,Stainless Steel 3.ISO9001 Diaphragm ... one and two-piece designs, with and without keyways, in aluminum and stainless steel and so on.Bulktek could produce any ... interested in then. Please don't hesitate to contract us. aluminum shaft collar