av永久免费观看,日韩在线精品视频,在线观看国产视频,国产精品久久片,国产毛片av网站,国产又粗又硬又黄又刺激,国产黄色片视频

Casus Products>> Casus

  The 42CrMoA in xingtai steel production has higher fatigue limit and multiple impact resistance after treatment, generally used in the production of 10.9 and 12.9 high-strength fasteners. Xingang`s  customer using the steel production is used for high-speed locomotive double connecting rod, the customer reflect the material strength, heat resistance, low temperature impact toughness has good performance, well received by customers.