Adjustable screw for sewing machine Surface :Plain Machined and turned SGS audited More than 20 ... experience 1,Name: Adjustable screw for sewing machine;adjustable screw;screw for sewing machine 2,For the similar screw,what can we ... of this kind of screw: Grade3.6,4.6,4.8,5.6,6.8,8.8,9.8,10.9,12.9,etcCarbon steelGr.B,Gr ... ,especially the cutting/turning parts.;; Adjustable screw for sewing machine