Sheet Metal – Corner Relief Options

Posted on March 4th by Dave Breiner, Synergis Manufacturing Solutions Engineer

What can you expect from a sheet metal bend corner? How will it look and how can you adjust them? Today I will give you some examples of bend corners and how they appear in the flat pattern and the folded model.Sheet Metal 1

I will begin by addressing how to change the GAP between 2 Flanges. The Material I am using is Stainless Steel 11GA which generally measures .125 inches thick. The default setting in our Rule set the Gap at the thickness of the material.Sheet Metal 2

Sheet Metal 3If you would like to close this Gap to aid in welding, you only need to enter a distance under the Seam Gap spacing. In this case, I will enter .01 inches.Sheet Metal 4

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There are several options under the corner tab for 2 and 3 bend intersections. I will review a few from each and show the results.

2 Bend Transition

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Round – A corner relief defined by a circular cutout in the flat at left. The cutout has a center placed on the intersection of the bend lines. Below are two views of the folded corner.Sheet Metal 7

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Square – A relief shape with a square cutout and centered on the bend line intersection of the two bend lines. Sheet Metal 10

 

 

Sheet Metal 11

 

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Tear – A relief shape defined in flat by extending the flange edges to their intersection. Named due to material failure caused by tearing across the bend zone in the folded model.

Sheet Metal 13Sheet Metal 14

 

Corner Relief Size

For a 2 bend intersection such as a Square or Round. When any two flanges or Contour Flanges meet at a 2 Bend corner, a parameter called CornerReliefSize is applied. This parameter sets the space between the Flanges. CornerReliefSize is defined by the Sheet Metal Rule, of which the default setting is 4 X the Thickness at below first. 2 X the Thickness is shown after.

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3 Bend Intersection

Use this option to define the Default corner relief to display in the flat pattern when 3 bends intersect.

Note: The folded model does not display the selected relief option.

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No Replacement As indicated, no replacement of the “as modeled” geometry is made in the flat pattern.

 

 

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Intersection A corner relief shape defined in the flat by extending and intersecting the flange edges.

 

 

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Full Round A corner relief shape defined in the flat by extending the flange edges to their intersection and then placing a fillet tangent to the bend zone tangency lines. Radius will likely be larger than what would be produced using the Round with Radius option.

 

Sheet Metal 20Round with Radius A corner relief shape defined in the flat by extending the flange edges to their intersection, and then placing a tangent fillet of the size specified. Radius will likely be smaller than what would be produced by the Full Round option. When using the Round with Radius relief shape a size field is available. By default is set to the thickness.

 

You may need a little trial and error to achieve the corner bend you are looking for but there are a lot of choices to aid in your decision making. I hope you found this article informative and helpful.

Till next time!

Dave

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