... are?We are Zhe Jiang Sinier Guide Co., Ltd, we produce cold rolled ball screw, linear guide ... Chinese government, has own workshop, we show our factory by this website link: http://www.tudou.com/ ... quality control. ZHE JIANG SENIRO GUIDE CO., LTD is the SOLE brand certificate holder for TBI brand ... TBI ball screw material GCr15 supply by Shanghai Bao steel Co., ltd The World Top Steel Enterprises. 4. ...