Tube bender

Choosing a tube bender by 4 criteria

Outside diameter and wall thickness. Bending Φ38 and bending Φ114 are two different classes of machine in force, structure and weight. Stainless needs more force than carbon steel at the same size.

Bend radius (CLR). The centreline radius you need. The smaller the ratio of radius to diameter, the harder the job — and below a certain point a mandrel becomes mandatory, otherwise the tube flattens or wrinkles.

NC or CNC. NC bends one angle at one radius with good repeatability, enough for simple parts. CNC controls feeding, tube rotation and bending together — needed when a part has multiple bends across multiple planes.

Number of axes and die stacks. Designations such as 2A1S, 3A1S and 4A2S describe the controlled axes and the number of die stacks. More stacks means several radii on the same part without stopping to change tooling.

A note on tooling: every diameter × radius combination needs its own set. If your parts involve many tube types, budget for this from the start.

Send the part drawing — for tube bending, a drawing is worth more than any description.