Difference between the hot bending and cold bending

  • Jack Lu 

Hot bending and cold bending are two different techniques used in metal bending processes. The fundamental difference between the two is the temperature at which the bending operation is performed.

4 roll plate rolling machine
4 roll plate rolling machine

What is the hot bending and cold bending?

  • Hot bending is a process in which the metal being bent is heated to a high temperature, typically between 800°C and 1200°C, to make it more pliable and easier to manipulate. This is commonly done in the presence of a furnace or heat source to ensure that the entire piece of metal is evenly heated before it is bent.
  • Cold bending, on the other hand, is a bending process where the metal is bent at room temperature or with only moderate heating. Unlike hot bending, cold bending typically involves using higher pressure to achieve the desired degree of bend as the metal is less pliable at colder temperatures.

Difference between the hot bending and cold bending

  • Hot bending is commonly used when bending larger and thicker pieces of metal or if greater degrees of curvature are required. Heating the metal to a high temperature softens the material and makes it more ductile and easier to form into the desired shape. This technique is typically used when working with industrial grade metals like steel, which have high melting points and can be challenging to work with through cold bending.
  • Cold bending is used for smaller or thinner metals that require less force to bend, such as aluminum or copper. This technique is used for precision metal forming where consistency and dimensional accuracy are key concerns. Additionally, cold bending does not alter the properties of the metal, making it ideal for parts that require specific physical properties.
  • Another difference between the two processes is the tolerances that can be achieved. Hot bending tends to have wider tolerances due to the effects of thermal expansion and contraction, while cold bending can achieve much tighter tolerances due to the absence of such temperature-dependent effects.

Final Words

The fundamental difference between hot bending and cold bending is the temperature at which the bending is performed. Hot bending, done at high temperatures, is typically used when working with larger or thicker metals or when greater degrees of bending are required, while cold bending, done at room temperature or with moderate heating, is commonly used when working with thinner or smaller metals that require precise dimensional accuracy. Each process has its unique advantages and limitations and is chosen based on the specific requirements of the project.