METALLKRAFT powered section and profile bending machines are designed to produce controlled curves in tubes, pipes, angles, flat bars, solid bars and square or rectangular hollow sections. They are used to manufacture arcs, rings, constant-radius curves, spirals and formed components for structural metalwork, architectural fabrication, furniture, maintenance, vehicle construction and general engineering. Unlike a fixed-die tube bender, a three-roll machine distributes deformation progressively along the workpiece and allows a wide range of large, adjustable radii without requiring a separate bending former for every diameter.
The operating principle generally uses three rolls. Two rolls feed the material while an adjustable roll applies the pressure required to develop the curve. The exact roll arrangement depends on the METALLKRAFT model, but the profile is normally passed through the machine several times while roll penetration is increased in controlled increments. Powered rotation provides a more consistent feed than manual operation, reduces physical effort and improves continuity when processing long workpieces, rigid sections or repeat production batches.
METALLKRAFT machines with mechanical top-roll adjustment give the operator direct control over penetration and are suitable for workshops handling varied jobs. Models with hydraulic adjustment provide more convenient and consistent pressure control for demanding sections, frequent cycles and repeatable settings. Hydraulic movement does not mean that the required radius should be formed in one pass. Excessive penetration can flatten a tube, distort the legs of an angle, twist an open section or overload the material and machine.
Horizontal and vertical working arrangements address different handling requirements. Vertical operation is convenient for many compact components and jobs where the profile can be guided laterally. Horizontal operation often makes heavy rings and large arches easier to support. When a METALLKRAFT machine can be used in both positions, the choice should reflect workpiece dimensions, mass, bending plane, available floor space and the ability to support both ends. Long stock must not hang from the rolls and act as a lever; adjustable stands or roller supports should follow the workpiece without restricting its movement.
Before bending, the material should be inspected and cleaned of scale, burrs and local deformation. The workpiece is placed in the correct roll groove and aligned with the bending plane. Side guides should control twisting without obstructing feed. Poor initial alignment can produce an unwanted helix, an out-of-plane arc or a changing radius. Marking reference lines and maintaining a consistent section orientation therefore improve both accuracy and repeatability.
Correct roll selection is essential. The groove must match the geometry and size of the profile and support it over a sufficient area. Round tube requires suitable support to limit ovalisation. Square and rectangular hollow sections need rolls that avoid excessive loading at the corners. Angles, channels and other open profiles may require dedicated rolls and lateral guides to prevent flange spreading or twisting. Universal tooling increases flexibility, while dedicated METALLKRAFT tooling is preferable when surface quality, tight tolerances or repeat production are priorities.
Machine capacity must always be interpreted in relation to material, section orientation and required radius. A profile does not have the same resistance about both axes, and high-strength steel requires more bending force than mild steel of the same dimensions. Wall thickness, temper, work hardening and weld quality also affect the result. Aluminium, copper and brass may be more ductile but can mark easily and show different springback behaviour. Stainless steel requires particular attention to force, work hardening and surface protection.
The achievable minimum radius depends on roll diameter, roll centres, frame stiffness, section modulus, wall thickness, section orientation and material ductility. A METALLKRAFT machine should consequently not be selected from one nominal tube dimension alone. The largest and most difficult planned section, the smallest required radius, the expected duty cycle and the required geometrical quality should all be evaluated. Professional users should retain a reasonable capacity margin rather than operate continuously at the machine’s limit.
Bending should normally be completed through several progressive passes. After a light initial setting, the workpiece is fed through the rolls and checked against a template, radius gauge or dimensional reference. Roll pressure is then increased in small steps. Where the machine and process permit, reversing the feed can simplify calibration. Recording roll position, pass count, section orientation and material specification provides a practical setup record for repeat orders.
Metal springs back after the load is released, so slight overbending may be necessary. The correction must be established by testing because it varies with alloy, section, wall thickness and radius. Excessive correction can create a local tight spot that is difficult to remove. Approaching the final radius in small increments gives the operator better control.
Three-roll machines normally leave straighter portions at the ends because the material cannot be fully bent outside the roll contact geometry. Components requiring a complete ring or a uniform curve to the edge may need additional stock for trimming, pre-bent ends or another compatible preparation method. Before a ring is welded closed, its diameter, flatness and continuity should be verified.
METALLKRAFT powered profile benders are not punching, drilling or shearing machines. If a component also requires holes, slots, notches or cut-outs, their manufacturing sequence must account for bending deformation. Features positioned near a highly stressed bend can stretch, become oval or initiate cracking. Depending on the design, they may need to be produced after bending or located with a calculated allowance.
Important purchasing criteria include capacity tables for each material and section type, shaft and roll diameters, roll spacing, available torque, working speed, reverse operation, motor power, frame rigidity, mechanical or hydraulic adjustment and side-guide design. Horizontal and vertical capability, pedal controls, position indication, optional tooling, operating footprint, maintenance access and the ease of roll changes also influence productivity and long-term flexibility.
A foot control available on various METALLKRAFT models allows the operator to control movement while guiding the material, but hands must remain outside the in-running nip points. Long sections sweep through a large area as they curve, so the operating zone must be kept clear and, where necessary, protected by barriers. Loose clothing, unsuitable gloves, hair and jewellery must be secured. Roll changes, cleaning and adjustments must only be carried out with the machine stopped and isolated from its power source.
Routine maintenance includes cleaning the roll grooves, removing scale and debris, lubricating the points specified by METALLKRAFT and checking shafts, bearings, transmissions, guides and adjustment mechanisms. Hydraulic models also require inspection of fluid condition, hoses, fittings and leakage. Excessive shaft play, non-parallel rolls or incorrectly set guides can cause tapering, twisting and poor repeatability. Rolls are not sharpened like shear blades; damaged or worn tooling should only be reconditioned or replaced in accordance with the manufacturer’s instructions.
METALLKRAFT powered bending machines are used for gates, railings, frames, canopies, greenhouses, signs, metal furniture, vehicle components, pipe supports, structural rings, decorative elements, plant equipment and household accessories. Their combination of powered feed, interchangeable tooling and controlled roll adjustment makes them valuable in fabrication shops, mechanical workshops, blacksmithing, maintenance departments, toolrooms, prototyping facilities and production environments working with steel, stainless steel and non-ferrous alloys.
Tadaah’s technical service supports machine selection by comparing the actual section, material, required radius, production frequency, working orientation and tooling requirements. This application-based approach helps identify the METALLKRAFT machine that offers the necessary capacity, control and safety without relying on a single nominal specification.
