... ISO9001:2008 5.inspection & warranty Namecarbon steel ball for curtainSize1/4",3/16",6mm.6.33mm,6.5mmGradeG1000Quality ... wearing, excellent surface, best quality and high hardnessApplicationMainly used for simply bearing, curtains, castor wheel, bicycle, aviation and ... termsL/C, T/T, D/P,Delivery10-15 days for one 20ft containerPort of shipmentQingdao/Tianjin/NingboAbout Taian Zhongrui Co., ...