| 摘要 |
PURPOSE: A hydraulic jack box wrench is provided to screw a bolt or a nut when a spring washer is not inserted into the bolt or the nut, or the bolt or the nut is tightly fastened by an air compressor. CONSTITUTION: A box jack comprises a box body(4), a box bar(6), a head ring(7), and a 10mm steel plate(15). The bottom of the box body is welded with the steel plate. The box bar is bent and is fitted in the head ring. The bottom of a jack body(10) is welded with the steel plate. |
