CY-J-15T/25T Jack is a type of front-chuck and common prestressed through-core Jack. It can be used not only for single hole tensioning, but also for multi-holes tensioning and pretightening, as well as for the treatment of prestressing pc strand anchors and removing wedges. By changing the tool wedges, the tension of stressing 7mm-16mm single wire and 12.7mm、15.24mm、15.7mm multi-bundle strands can be satisfied. It is widely used in bridges, buildings, prestressed concrete structures, component workshops, hydraulic structures and engineering tests. This type of Jack is designed with a new structure. The front-chuck design shortens the reserved length outside of the prestressed Anchorage and greatly saves the steel strands consuming. The Jack main parts are made of high quality alloy steel forging and heat treatment, thus prolonging the durable years, making the whole machine small in size, light in weight and convenient in operation.