What is the difference between cold bending and hot bending?

Cold bending and hot bending are methods used to bend metal.

In cold bending, the metal is bent at room temperature using a press or bending machine. This method is typically used for materials less than 3/8" thick and can be used to produce a variety of shapes such as angles, channels and tees. It is a good method for producing small, precise bends with minimal deformation to the metal. It is also suitable for brittle materials or materials that may crack when bent at higher temperatures, such as certain types of stainless steel.

Hot bending, on the other hand, is a method where the metal is heated to a specific temperature prior to bending. This method is typically used for materials that are more than 3/8 of an inch thick or for materials that are difficult to bend when cold, such as certain types of aluminium or steel. By heating the metal, the fibres within the material will become malleable and the metal can be bent without cracking or breaking. The heated metal is then bent using a press or bending machine.

Hot bending is also suitable for large scale and complex parts or where large radii are required. Some specific alloys such as titanium, Inconel and Hastelloy cannot be cold bent and require hot bending. In addition, in some cases it is necessary to anneal the material before or after bending to reduce the stresses in the metal.

Hot bending typically offers greater accuracy and consistency than cold bending, producing a better finished product with a more consistent grain structure. However, it also requires specialised equipment and a higher level of skill to perform, and it can be more expensive and time-consuming than cold bending.

In contrast, thermal induction bending is done using the above thermal bending method. During induction bending, high frequency induction electricity is used for local heating. Pipes, tubes and even structural shapes (channels, W & H profiles) can be bent efficiently in an induction bending machine. Thermal induction bending is also known as induction bending, incremental bending or high frequency bending. For larger pipe diameters where cold bending methods are limited, thermal induction bending is the most preferred option. The thermal induction bending process is carried out by locally heating the pipe, allowing it to be bent effortlessly. Induction coils are placed around the pipe to be bent, heating the circumference of the pipe to 850 - 1100 degrees Celsius.

We are pleased to quote for API5L Gr heat induction bends: B, X42, X46, X52, X60, X65 and European standard pipes. Thermal induction bending (above 750°C) protects the mechanical properties of the material and our factory also offers post-bending heat treatments such as normalisation and stress relief heat treatments. During final inspection, we perform dimensional and visual control of the welds, hydrotesting and 100% non-destructive testing to provide minimum bending tolerances.

Our bending processes and thermal induction bending can work with you to bring success to your project, large or small. We believe we have guaranteed processes and exacting standards, not to mention our years of success! If you have any questions, please contact us today.