Lead and backup tong-men should not stand between the two pipe tongs while the driller is making up or breaking out pipe or collars.
当司钻正在上卸钻杆和钻铤时，内外钳工不要站在两个大钳之间。
2
The utility model relates to a bi-directional gad tong with a trapezoid lead screw and pertains to a machining tool used for replacing an old gad tong (commonly known as a vise).