A punch press is a type of machine press used to cut holes in material. It can be small and manually operated and hold one simple die set, or be very large, CNC operated, with a multi-station turret and hold a much larger and complex die set.
Punch presses are large machines with either a ‘C’ type frame, or a ‘portal’ (bridge) type frame. The C type has the hydraulic ram at the top foremost part, whereas the portal frame is much akin to a complete circle with the ram being centered within the frame to stop frame deflection or distortion.
The punch press is characterized by parameters such as:
- Frame type
- Mechanism of delivering power to the ram (mechanical, electro-mechanical or hydraulic)
- Size of working area (e.g., 2500 x 1250 mm)
- Single or multiple station
- Force rating (for example, 20 tons)
- The type of tool shop and its capacity (e.g., store revolving type, capacity 34 tool)
- Speed or productivity (typically characterized by the speed of strokes with a step movement of 25 and 1 mm)
- Speed of movement without shock (speed-load displacement)
- Maximum weight of workpiece
- Safety features
- Power consumption
- The type of software
Punch presses are usually referred to by their tonnage and table size. In a production environment a 30-ton press is mostly the machine used today. The tonnage needed to cut and form the material is well known, so sizing tooling for a specific job is a fairly straightforward task. According to the requirement the tonnage may even go up to 2000 to 2500 ton presses.