Sheet Metal Design Tips for Easy Manufacturing
01. Bend Relief:
Bend relief is the notch that needs to be created for sheet metal bending. For better clarity see the picture below:
The flange which does not have relief will result in a greater amount of distortion or tearing of the adjacent material.
As per sheet metal design thumb rules, the depth of bend relief should be greater than or equal to the inside bend radius of the bend and the width of the bend relief should be the same as the sheet metal thickness or more.
02. Minimum Hole Size for Sheet Metal:
While placing the holes in your drawing please keep in mind that, you should not make holes small enough to break the tool. As you reduce the size of the sheet metal hole, smaller size punches will be required. If the size of the punch becomes too small it may break during operation.
Sheet metal design rule of thumb in this case is: The diameter of the hole should be equal or more than the thickness of the sheet metal.
03. Minimum Clearance between a Hole and Bend:
It is very important to maintain enough clearance between a holes and bend for sheet metal design, or else the hole will get deformed like below:
The sheet metal design rule of thumb in this case is: The distance between the sheet metal bend line and edge of the hole should be two times or greater the thickness of the sheet metal.
04. Minimum Sheet Metal Bending Radius:
Minimum sheet metal bend radius depends on the selection of tool and the process. The more ductile the sheet metal, the smaller the inner bend radius is possible. The sheet metal design rule of thumb in this case is: The minimum bend radius for mild steel sheet metal should be equal to the thickness.
05. Minimum Flange Width:
While specifying flange widths in your drawing, please ensure that the width of the flange does not go below four times the thickness of the sheet metal. Otherwise, the tool will create marks on the sheet metal surface while manufacturing.