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 50BV30 product produced by Xingtai steel has the advantages of stable composition, low harmful elements, high purity of steel, small decarburization layer and less surface defects. After spheroidizing annealing, the cold heading property is excellent, and the product has good hardenability. A customer of Xingtai steel makes high strength tool sleeve with this product.