What is the difference between induction bending and cold bending?

Induction bending heats a narrow band of the pipe wall with an induction coil so the metal moves without thinning, which is what makes large diameters and heavy walls possible. Cold bending forms the section around a die at room temperature, which is faster and cheaper on smaller sizes but limited by how far the wall will stretch before it collapses.

What is a centerline radius?

The radius of the arc measured to the middle of the pipe, not to the inside or outside face. It is usually quoted as a multiple of the pipe diameter, so a 3D bend on 12 inch pipe has a 36 inch centerline radius. It is one of the five numbers we need to quote.

Can you bend shapes other than round pipe?

Yes. Channel, angle, wide flange, and round and finned tube. Tell us the section and the axis you want bent about, because the strong axis and the weak axis behave very differently.

How tight a radius can you bend?

It depends on the diameter, the wall and the material together, not on any one of them. Send the three and we will tell you the tightest radius that holds your wall thinning and ovality limits, and what it costs.

The induction heat band glowing orange around a large-diameter pipe as the bend is formed

Capabilities

Types of Bends

Heat induction bending, coiling and cold bending, from standard bends to the ones thought to be impossible.

Three processes, and how to tell which one you need

The method follows the pipe, not the other way round. Wall thickness, centerline radius, material and schedule decide it between them, and the wrong choice shows up as a collapsed wall, an out-of-round arc or a price nobody wants to pay.

As a rule of thumb: heat induction bending is for large diameters and heavy walls, where the metal has to be soft to move without thinning. Coiling is for continuous runs of tube or pipe wound to a pitch, for heat transfer. Cold bending is for smaller diameters, tighter radii and repeat production, where the section is small enough to be formed around a die at room temperature.

American Pipe Bending runs all three on one floor, which is the part that matters to a buyer. A piping package rarely contains one size, and splitting it between a large-bore shop and a small-bore shop means two quotes, two schedules and two sets of paperwork. We are also able to bend channel, angle, wide flange, and round and finned tube, not only round pipe.

Pick the process that fits the pipe

Send us the drawing and our team will tell you which one, and why.

Induction Bending

A narrow band of pipe is heated by induction coil and bent in one continuous pass. Large diameters, heavy walls, minimal ovality and thinning.

Induction capabilities

Helical Coiling

Continuous coils for boilers, heat exchangers and process heaters, wound to your pitch and diameter with consistent spacing from first turn to last.

Coiling capabilities

Cold Bending

Rotary draw bending at room temperature for tighter radii on smaller diameters, structural shapes and production runs that need repeatability.

Cold bending capabilities

The five numbers, and why they are the only ones we ask for

Outside diameter, wall thickness, centerline radius, bend angle and tangent length describe a bend completely. Everything else on a drawing is context.

Centerline radius is the one most often confused. It is measured to the middle of the pipe, not to the inside or outside face, and it is usually written as a multiple of the diameter. A 3D bend on 12 inch pipe has a 36 inch centerline radius. Getting that wrong by a factor of two is the single most common error on an incoming enquiry.

Tangent length is the straight left on each end. It matters for two reasons: the machine needs something to hold, and the tangent is usually where the weld goes. A drawing that dimensions a bend with no tangent is describing something nobody can make.

Bend angle is measured as the change in direction, not as the included angle. A 90 degree bend turns the pipe through a right angle.