亚洲裸体视频,一级毛片在哪里看,国产素人在线,国产精品丝袜久久久,亚洲无砖砖区一二区免费,亚洲а∨天堂久久精品喷水,91网站在线播放

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.