亚洲天天骚女现场视频,www.888日本,亚洲第一天堂无码专区日韩,免费一级黄片视频在线观看无码,亚洲日韩线精品一区一区一区,一级无码日韩毛片,国产免费美女被艹视频

Main Products
Products Grade: 12CrMo4
Specifications: φ5.5~16mm
Applied Standard:  agreement
Characteristics: It's used to produce the engine vavle spring retainer
Applications: Common parts
Use of Products: 12CrMo4 is a commen steel grade which used to producethe engine vavle spring retainer. 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 ,stable heat-treatment properties and good hardenability