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: 20CrMnTi
Specifications: Φ5.5-28 mm
Applied Standard:  GB/T 3077
Characteristics: The product is mainly used to produce gear and various kinds of machine-parts.
Applications: Common mechanical steel
Use of Products: By special process, gear steel has characteristics of uniform-chemicalcomposition, narrow temperature range for hardenability, fine grain size, high purity, good surface quality and excellent hot heading properties. It can meet the requirement of gear product.