Profile Bending Machines for Tube and Profile

How to choose a profile bending machine

A profile bending machine rolls tube, box section, angle, flat bar, channel and beam to a radius: the workpiece is passed between three rolls and takes the required curvature over several passes. This is how arches, rings, rolled sections, spirals and structural elements are made. The catalog carries our own LUNA Helix machines and Italian MG AR-ARL ones: shafts from 30 to 530 mm and drives from 4 to 218 kW.

A section bender or a tube bender

These are different machines. A tube bender wraps the tube around a former in one movement, producing a constant radius and an elbow, often with a mandrel inside so the wall does not collapse. A profile bending machine rolls the workpiece between rolls: the radius is set by the roll position and can be large, variable or closed into a ring. Arches, rings, spirals and long sweeping curves need a three-roll profile bending machine. For elbows and batches of identical tube bends the section also has the NARGESA CC CNC tube benders: no mandrel, up to 180°, steel tube up to Ø90 mm.

There are three three-roll lines in the catalog: LUNA Helix, MG AR-ARL and the Spanish NARGESA MC — eight models for tube up to Ø50–101.6 mm, from manual roll adjustment to an ESA S625 CNC. A digital radius gauge is available for the NARGESA benders: 100, 200 and 300 mm arcs, inside and outside radii from 55 to 11,250 mm — the radius is checked without taking the part off the machine.

How to tell whether a machine will take your section

The capacity of a profile bender is measured not by tube diameter but by the section modulus W in cm³, taken from the tables for your profile. The MG cards give a range: the MG AR-ARL 60 10–18 cm³, the MG AR-ARL 140 45–95 cm³ and the heaviest MG AR-ARL 530 2500–15,000 cm³. It is a range rather than a single figure because the limit depends on the steel grade, the orientation of the section and the radius required.

The same section can be bent in different planes, and W differs between them: a 60×40 box section bent on edge and bent flat are two different jobs for the machine. That is why an enquiry should state not only the section but also exactly how it has to be bent.

What else to compare

• Shaft diameter. It is the main figure in the model name: LUNA Helix from 30 to 180 mm, MG AR-ARL from 60 to 530 mm; the NARGESA MC have 40–80 mm shafts. A thicker shaft means a stiffer machine and a larger section, but also a different weight: from 920 kg on the MG AR-ARL 60 to 297 t on the AR-ARL 530.
• How many rolls are driven. On the LUNA Helix 40 the two lower rolls drive, on the Helix 60 and above all three do. Three driven rolls pull a heavy section better and slip less on a thick wall.
• Control. The Helix 30 and 40 are manual; from the LUNA Helix 50 up the top roll moves hydraulically, with NC as an option. A digital readout is optional on the smaller models and fitted as two indicators on the Helix 80 and above: without it the same arc cannot be repeated twice.
• Side supports. Angle and channel twist sideways under load. On the Helix 80 the supports are mechanical, on the Helix 160 and 180 hydraulic three-axis ones. For asymmetric sections they are not an extra but a condition for a clean curve.
• Horizontal or vertical. All the Helix models work in both positions. Vertical is more convenient for long workpieces: the section stands instead of lying on the floor, and one operator can guide it more easily.
• Rolls. The roll set is matched to the section: tube, square, angle with the leg inwards or outwards — each needs different tooling. It should be budgeted together with the machine.

Common mistakes

• Comparing machines by tube diameter instead of section modulus W: a 60×60×2 and a 60×60×4 box section are different jobs.
• Not saying in which plane the section is bent: on edge the same profile needs a noticeably larger machine.
• Forgetting the minimum radius: on a tight radius a thin wall wrinkles, and that calls for rolls made for the specific section or a different process.
• Costing the machine alone — without rolls, side supports and the digital readout if the arcs have to repeat.

Send the section and material grade, the plane of bending, the radius required and the number of parts — we will work out the section modulus, select the model, the rolls and the supports and cost delivery and commissioning. If sheet has to be rolled into a shell, you need plate rolls; for straight bends to an angle, press brakes; and blanks can be cut on band saws or laser tube cutters.