成人免费a视频,李雅在线观看一区国产,五月婷婷狠狠,精品国产自在2o18,狼伊人,五月天丁香婷婷网,久久亚洲精品无码观看不卡

Main Products
Products Grade: GCr15Z
Specifications: φ5.5～26mm
Applied Standard:  agreement
Characteristics: The product is used to produce balls and rings of bearing,which need long life and high reliability.
Applications: Auto Bearing steelRailway bearing steel
Use of Products: GCr15-L is better than GCr15 of GB/T18254 on chemical、non-inclusion、Carbide homogeneity、decarburization and surface quality。