... ,51300,51400,DAC,BC, etc. Ring MaterialChrome Steel ,Carbon steel,Stainless steel Tolerance gradeGB/T307.1-205 ID Size 10mm ... , adhere to the "honesty, practical, win-win" business philosophy, to provide the customers with best service and the ... the company constantly improve themselves, growing, and the business have involved the steel industry, port machinery, petroleum chemical industry, automobile ...