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How to bend stainless steel sheet metal parts?

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Stainless steel has a wide range of uses and is a common material in our lives, such as security windows, bus shelters, shelves, etc. Due to the high yield point, high hardness, and significant cold work hardening effect of stainless steel, stainless steel has some obvious bending characteristics. 

How to bend stainless steel sheet metal parts

Four difficulties in bending stainless steel

  1. The thermal conductivity of stainless steel is worse than that of ordinary low-carbon steel, and the elongation is low, resulting in a large deformation force; 
  2. Compared with carbon steel, stainless steel sheet has a strong spring-back tendency when bending; 
  3. Due to the low elongation of the stainless steel plate, the bending angle R of the workpiece should be larger than that of the carbon steel during bending, otherwise, there may be cracks; 
  4. Due to the high hardness of the SUS304 stainless steel plate, the cold work hardening effect is significant. Therefore, when selecting a bending tool, tool steel with a heat treatment hardness of 60HRC or more should be selected, and its surface roughness is an order of magnitude higher than that of a carbon steel bending tool.

Four tips for bending stainless steel 

In view of the above characteristics of stainless steel, generally speaking for its bending: 

  1. Under the unit size, the thicker the plate, the greater the required bending force, and as the plate thickness increases, the margin of the bending force should be larger when selecting the bending equipment; 
  2. Under the unit size, the greater the tensile strength, the smaller the elongation, the greater the required bending force, and the larger the bending angle; 
  3. When the thickness of the plate in the design corresponds to the bending radius, according to experience, the expansion size of a bending workpiece is the addition of the right-angled sides minus the two plate thicknesses, which can fully meet the design accuracy requirements, and the expansion amount can be calculated according to the empirical formula. Simplify the calculation process and greatly improve production efficiency; 
  4. The greater the yield strength of the material, the greater the elasticity and recovery. In order to obtain a 90-degree angle of the bending part, the angle of the required pressing knife should be designed to be smaller. Compared with carbon steel, stainless steel with the same thickness has a larger bending angle. Special attention should be paid to this point, otherwise, there will be bending cracks, which will affect the strength of the workpiece.