A hydraulic punch press for use with a set of interchangeable tool assemblies for boring, cutting, bending, or otherwise working on semi-finished steel frame members or the like. Included are a punch press section having a hydraulic cylinder for driving a tool assembly, a toolholder section having a turntable on which tool seats are arranged radially for carrying a set of tool assemblies, and a guideway section for transfer of a tool assembly between punch press section and toolholder section. The turntable is rotatable to bring any of the tool seats to a tool transfer position where a tool assembly may be transferred to or back from the punch press section by way of the guideway. Each tool assembly is normally locked to one tool seat by two lockpins. One lockpin is automatically released when the associated tool seat comes to the tool transfer position, and the other when a positioning arm is manipulated to retain the tool seat in that position. Additional embodiments are disclosed.
