草久久精品,成人久久亚洲,日本一道本在线视频,国产精品99一区二区,一区二区三区综合,久久精品5,自拍偷拍你懂的

Main Products
Products Grade: 42Cr9Si2,45Cr9Si3,40Cr10Si2Mo
Specifications: φ5.5-φ16mm
Applied Standard:  agreement
Characteristics: Engine Valve
Applications: high-end parts
Use of Products: Engine Valve steel with high strength, high temperature resistance, used in the production of engine intake and exhaust valves and other high temperature resistant parts.