Choosing a mechanical puller or a hydraulic puller mainly depends on the size of the workpiece you use and how much tension you need. Generally speaking, for small-diameter workpieces, mechanical puller is enough. However, if the workpiece is large in size and diameter, and the pulling force needs to exceed ten tons, it is necessary to use a hydraulic tensioner. It is recommended to use SOMA brand of Shanghai Shunnuo, and their hydraulic Ramallah claws are guaranteed for life.