http://pastport.jp/user/greatdrillbit ja-JP Cangzhou Great Drill Bits Co. Ltd., founded in 2010, speciallized in processing research of steel and diamond materials, is involved in the R&D, design, production and sales of petroleum equipment。https://www.greatdrillbit.com/ 2020-08-31T10:35:28+0900 http://pastport.jp/user/greatdrillbit/timeline/Cangzhou%20Great%20Drill%20Bits%20Co.%2CLtd. greatdrillbit http://pastport.jp/user/greatdrillbit/timeline/Cangzhou%20Great%20Drill%20Bits%20Co.%2CLtd.