日韩欧美在线视频免费,黄色国产91,欧美日韩亚洲国产,最近中文字幕在线,性高爱久久久久久久久,亚洲精品午夜不卡,一区二区三区福利视频

Main Products
Products Grade: SCr420B
Specifications: φ16～38mm
Applied Standard: 
Characteristics: This product is used to produce high strength bolt of class 12.9.
Applications: Common partsCommon fastenerHigh strength fastener
Use of Products: SCr420B is a steel grade which used to produce high strength bolt of class 12.9 .This product has characteristics of uniform-chemical composition, low percentage of harmful elements, high purity, slight decarburisation, good surface quality. After spheroidize annealing, this product has the characteristics of good cold heading properties. And the product has excellent hardenability.