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
steel for machine structure Products>> Main Products>> steel for machine structure
Products Grade: 20Cr2MnMoA
Specifications: φ20~28mm
Applied Standard:  agreement
Characteristics: this product is used to produce continuous sucker rods.
Applications: Sucker rod
Use of Products: This grade has the feature of stable chemical composition, low harmful elements(O、N) and nonmetallic inclusions, minor decarburization, good surface quality,good plasticity and notched bar impact strength after heat treating.Now our product is used in Shengli Oil Field.