国产精品福利自产拍在线观看,亚洲欧美精品伊人久久,日本一区午夜艳熟免费,再深点灬舒服灬太大了少妇

軸套材料：

直淬鋼(Dierct harden steel): GCrlS ( 52100)??42CrMo (4140 )??45(1045)

滲碳鋼(Carburizing steel): 20Cr ( 5120 )??20CrMo(4118)??20CrNiMo(8620H)

銅(Copper):ZCuZn24AI6Mn3Fe3??ZCuAI9Fe4Ni4Mn2

彈簧鋼(Spring steel):65Mn??50CrVA??60Si2MnA

產(chǎn)品特點(diǎn)：無(wú)潤(rùn)滑槽和孔