Choosing pull wheel system, must consider the following three important basic elements:

1,The drawing ability

The drawing on wheel can produce the size of the force. Generally speaking, work ability can be made of a task need is determined by the diameter of the shaft rod drawing parts, for the manual wheel, pull pull the diameter of the wheel center screw should be at least as one half of the shaft lever are unloaded parts. For hydraulic wheel, with tons of work ability for shaft rod millimeters in diameter between 0.28 to 0.40 times.

2, Drawing depth

Refers to the wheel base to pull chela plane distance. Pull the wheel radius must be equal to or greater than by the size of the corresponding part drawing parts.

3, Drawing outside diameter

The distance between the clamp claw, pull out a distance of the wheel need bigger than was the width of the drawn parts.