Jack is divided into mechanical jack and hydraulic Jack, the principle is different. The principle of hydraulic jack is based on Pascal principle, namely: the pressure of the liquid everywhere is consistent, so that in a balanced system, more than the smaller piston imposed on the pressure is smaller, and the large piston exerted pressure is also relatively large, so that the liquid can keep static. So by passing the liquid, you can get different pressures on the different end, so that you can achieve a transformation. The hydraulic jack we often see is the use of this principle to achieve the power of transmission. Mechanical Jack adopts the principle of mechanical, to reciprocating the handle, pulling claw to promote the ratchet clearance rotation, small umbrella gear drive large umbrella gear, lifting the weight screw rotation, so that lifting sleeve to get up or down, and achieve lifting pull function. But not as easy as hydraulic jack. Hebei Shengtong also can provide kinds of lifting clamps.