If neither part is threaded a bolt must be used: this consists of a screw with a hexagonal head.
如果两者皆不的部份被穿线于门闩一定被用：这用一个六角形的头有螺丝钉。
2
The flat gasket and the spring gaskets are arranged on the bolt between the ante-receding expansion pipe and the hexagonal cap of the bolt.
平垫片和弹簧垫片，它们安装在防退膨胀管和螺栓六角帽之间的螺杆上；
3
The utility model discloses a force driven fixing structure for axle center which comprises gear or synchronous belt wheel, axle clamp and inner hexagonal head bolt.