... Steel Tower Co., Ltd. Qingdao Histro Steel Tower Co., Ltd. And Qingdao Histro Steel Pipe Co.,Ltd Qingdao Histro Steel Tower Co., Ltd ... . is headquartered in Beiguan Industrial Park Jiao Zhou City, Qingdao; our production base takes up an area of 120,000 ... and Keeps Promise' by the Industrial and Commercial Bureau of Qingdao from 2001 to 2009 in succession. We get the ISO9001 ...