... zinc alloy, brass,copper,acryl,iron,stainless steel,etc.3.Technic: plating. or painted.4.Size: 10mm-30mm ... samples for you approving,our sample time is 3-5days.After you approve our sample,then we ... the 14 #, 16 #, 18 #, 20 #, 60 #, etc.3)The standard formula: diameter = 0.625 Model * (mm).If ... ,snap buttons,iron button.rivet ,eyelet.belt buckles and so on, our products are all approved with ROHS test ...