Folding machines for sheet metal work
A folding machine, also known as a swing-beam folding machine, is one of the core machines for bending sheet metal. Unlike a press brake, no punch forms the workpiece; instead a folding beam clamps the sheet and swings it upwards around a fixed edge. The method is simple, it protects the sheet surface and it keeps bending and set-up times short. That is how edges, hems, seams and multi-bend profiles are made for roofing and cladding, ventilation and general metalwork. KNUTH supplies folding machines in several builds and sizes, from the manual machine through to the CNC-controlled double bender.
How a folding machine works and how it is built
A folding machine is built around three beams. The lower beam carries the sheet, the clamping beam holds it down on the bend line, and the folding beam swings upwards to form the edge. The usual method is free bending:
- Load and set the stop: the sheet is positioned on the lower beam against the rear stop.
- Clamp: the clamping beam fixes the sheet exactly on the bend line.
- Fold: the folding beam swings up and bends the sheet to the required angle.
Because the clamping beam only holds and does not press, sensitive surfaces stay undamaged. The operator sets repeatable edges through the stop and the fold angle. For hems, meaning tightly folded-back edges, and for pans, segmented tooling is used.
Types and versions
Folding machines differ mainly in the drive and in the folding principle:
- Manual folding machine: clamping and folding are done by hand. Robust, simple and economical for one-off parts, repairs and the workshop.
- Motorised and hydraulic folding machine: a drive handles the clamping and folding, which takes the load off the operator and speeds up repeating bends.
- CNC folding machine: a control system drives the rear stop, fold angle and bend sequence by programme, securing repeatability on complex parts and higher quantities.
- Double bender (up-and-down folding machine): the folding beam bends both upwards and downwards, so the sheet does not have to be turned over. That noticeably shortens work on parts with opposing edges.
With segmented folding beams, pans and multi-sided structures can be produced. The builds and working lengths currently available are shown in the product cards above.
Folding machine or press brake: which one fits
Both machines bend sheet metal, but on different principles, and that decides the choice:
- Folding machine: a folding beam swings the clamped sheet upwards. Strong on long edges, thin to medium sheet, hems and gentle handling of sensitive surfaces. No tool change is needed for different angles.
- Press brake: a punch presses the sheet into a die. Strong on thick sheet, high press force and tool-bound profiles. Details on the press brakes page.
As a rule of thumb, long clean edges and hems point to the folding machine, while thick sheet and tool-bound profiles point to the press brake. A double bender combines up and down folding in one machine and is the flexible choice for changing workpieces.
Technical features and machine sizes
Two figures drive the choice. The working length has to match the longest sheet edge, and the bending capacity has to match the combination of sheet thickness and material. As a guide, thicker sheet and longer edges call for a stronger machine. Further features include the adjustable rear stop for accurate positioning, fine setting of the fold angle, and segmented tooling for pans and hems. KNUTH supplies folding machines from the compact size for the workshop through to the long machine for metal and facade work. The exact values for each series are given in the product cards above.
Applications and industries
The folding machine is at work wherever sheet metal is folded cleanly and over long lengths:
- Roofing and sheet metal roofing: gutters, seams, coping and folded parts for roof and facade
- Facade and ventilation work: cladding, ducts and formed parts from thin sheet
- Metal and enclosure building: housings, covers and profiles with clean edges
For cutting the blanks before folding, KNUTH supplies guillotine shears, and for rolling sheet, plate rolling machines.
Tooling, rear stop and accessories
The result from a folding machine depends on the stop and the tooling. An adjustable rear stop gives repeatable edge dimensions, segmented folding beams allow pans and multi-sided structures, and matching clamping tools hold the sheet gently in place. Matching tooling and accessories can be quoted together with the machine.
Why KNUTH
KNUTH is an established supplier of machine tools with a coordinated range for sheet metal work. Each machine is given a documented inspection and shipped CE-compliant. You get personal advice on the right working length, bending capacity and equipment instead of a bare catalogue choice, along with tooling and accessories from a single source. Around 1,000 machines are ready to ship from the European central warehouse in Germany. For an overview of the full sheet metal range, see the sheet metal processing category.
Service, spare parts and availability
Service runs through our own service network, with our own service engineers looking after the machines in the field. Commissioning and operator instruction for your team are available as a separate service. A ten year spare parts supply commitment applies. For help sizing your folding machine, choosing tooling or checking availability, reach us through the contact page.
Further Machine Categories at a Glance
Here is an overview of our machine range. Select a category to learn more about individual machines and their technical data.
