镀锌六角螺栓螺帽
galvanized mild steel hexagonal bolt and nut
镀锌瓦楞螺栓螺帽
galvanized mild steel roofing bolt and nut
缸盖螺栓螺纹
cylinder head bolt thread
head bolt thread
连杆螺栓螺纹
connecting rod bolt thread
rod bolt thread
螺栓螺母机
bolt and nut making machine
排气岐管螺栓螺纹
exhaust manifold bolt thread