Sheet metal bending radius is a value required in sheet metal drawings, which is difficult to determine in actual processing.
In fact, this sheet metal bending radius is related to material thickness, bending machine pressure, and bending die lower die slot width. What is the specific relationship? Let’s study it today:
According to experience in actual sheet metal processing: when the plate thickness is generally not more than 6mm, the inner radius of sheet metal bending can be directly used as the radius when bending.
When the plate thickness is greater than 6mm and less than 12mm, the inner bending radius of the plate is generally 1.25 to 1.5 times the plate thickness. When the plate thickness is not less than 12mm, the inner bending radius of the plate is generally 2 to 3 times the plate thickness.
When the bending radius is R=0.5, the general sheet metal thickness T is equal to 0.5mm. If a radius size greater than or less than the plate thickness is required, a special mold is required for processing.
When the sheet metal drawing requires the sheet metal to be bent 90°, and the bending radius is particularly small, the sheet metal should be grooved first and then bent. Special upper and lower dies of the bending machine mold can also be processed.
The bending radius of the sheet metal is related to the width of the groove of the lower die of the bending mold.
Through a large number of experiments in sheet metal processing, it is found that the groove width of the lower die of the bending mold has a certain relationship with the size of the bending radius. For example: 1.0mm sheet metal is bent with an 8mm groove width, so the bending radius pressed out is R1 in the ideal state.
If a 20mm groove width is used for bending, since the upper die moves downward during bending, the depth of the stretched sheet reaches a certain angle. Then we know that the area of the 20mm wide groove is larger than that of the 8mm wide groove. When bending with a 20mm wide groove, the stretching area also increases and the R angle also increases.
Therefore, when there is a requirement for the bending radius of the sheet metal and it does not damage the bending machine mold, we try to use a narrow groove for bending. Under normal circumstances, it is recommended to operate according to the standard ratio of plate thickness to slot width of 1:8. The minimum ratio cannot be less than 1:6. Sheet metal bending can be appropriately smaller, and cannot be less than 1:4. Suggestion: If the strength allows, it is preferred to use the method of planing grooves before bending to make a small sheet metal bending radius.
The bending radius of sheet metal processing depends on the material thickness and the width of the bending slot. The simple, convenient and rough method is:
Generally, when the plate thickness is not more than 6mm, the inner bending radius of the plate can be directly used as the plate thickness size when bending. When the plate thickness is greater than 6mm and less than 12mm, the inner bending radius of the plate is generally 1.25 to 1.5 times the plate thickness. When the plate thickness is not less than 12mm, the inner bending radius of the plate is generally 2 to 3 times the plate thickness.
Here is our Custom Sheet metal bending Display：
