Ycw60 / 80B series jack is a new type of through core prestressed jack which is reformed from the original ycw60 / 80A type. It has small volume, light weight and superior performance. It is mainly used in post tensioned prestressed construction engineering. The stress bars of finish rolled deformed steel anchors and end bar anchorages can be tensioned, and steel wire bundles with upsetting anchorages can be tensioned.