久久中文字幕一区二区三区,日本99热,高清av一区,日韩狠狠操,久久久一本精品99久久精品66,1级片网站,aaaaaaa欧美黄色大片

　　Entrusted by Hebei Provincial Market Supervision Administration, in July 2019, Product Quality Supervision and Inspection Institute appointed the National Product Quality Supervision and Inspection Center for Steel (Tangshan) to conduct a spot check on high-carbon chromium bearing steel in our company. 24 different samples from the same batch are directly extracted from assembly line. As a result, all 32 items in 8 major items up to the standard of GB/T18254-2016, which shows the quality of our bearing steel products is excellent and reliable.