Adjustable screw for sewing machine Surface :Plain Machined and turned SGS audited More than ... experience 1,Name: Adjustable screw for sewing machine;adjustable screw;screw for sewing machine 2,For the similar screw,what can ... .8,10.9,12.9,etcCarbon steelGr.B,Gr.C,Gr.D,Gr.36,Gr.58,1010,1015,1016,1020,1045,etcAlloy steel4130 ... ,especially the cutting/turning parts.;; Adjustable screw for sewing machine