久久中文字幕一区二区三区,日本99热,高清av一区,日韩狠狠操,久久久一本精品99久久精品66,1级片网站,aaaaaaa欧美黄色大片

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