91中文精品,污污的视频免费在线观看,91就要激情,精品黄色网,欧美精品看片,久久久久久a亚洲欧洲aⅴ,天天干天天色综合网

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