Sheet Metal Material Selection Sheet thickness and material can be selected using:
Study existing products
Inside Bend Radius
Recommended inside bend radius for sheet metal parts should be equal to material thickness. But for harder materials (e.g. CRCA) inside bend radius equal to 0.65 times of sheet thickness is also enough.
Minimum Bend/Flange Length Guidelines
Min. flange Bend length = 3X Sheet Thickness + Bend Radius
Minimum Hole Diameter Guidelines
For softer materials, recommended minimum hole diameter is equal to sheet thickness. Whereas for harder materials recommended minimum hole diameter is equal to two times of sheet thickness.
Hole/Slot Distance from Bend Edge
Minimum distance between hole/slot edges to bend edge is maintained to avoid metal distortion, deformation and fracturing. Recommended minimum distance between hole /slot edge to bend in sheet metal design is three times the sheet thickness plus bend radius.
Center to Center Distance Between Two Holes
Minimum center to center hole distance is maintained to avoid metal distortion, deformation and fracturing. Minimum distance between two hole center during sheet metal design should be equal to sum of hole radius plus two times the sheet thickness.
Recommended Distance = Radius of Hole1 + Radius of Hole2 + Sheet Thickness
Effect of Grain Direction in Sheet Metal Bending
During sheet metal processing (rolling operation), material grains are arranged in the direction of rolling. When Sheet metal is bending perpendicular to rolling direction grain rearranges. That has negligible effect on part strength. Whereas bending parallel to rolling direction can lead to cracks because of destruction in grain structure.
Relief height is generally kept greater than two times of sheet thickness plus bend radius.
Extrude Hole Size & Position Guidelines
Creating extruded hole using punching process requires extreme pressure/Force. Extruded hole close to the part edge can lead to sheet metal deformation or tearing. Therefore minimum distance between extruded hole to edge if maintained.
Extruded hole to part edge (B) = 3T + D/2
Center of extruded Holes (A) = (5 + Hole Dia + 2T) Extruded Hole and bend edge (C) = 3T + R + D/2
Round Emboss Design Guidelines
A – Distance from Emboss to part Edge = 3T + D/2 B- Distance between Two Emboss = (5 + D) C- Distance between Emboss and Sheet Metal bend = 3T + R + D/2
Dimple Feature Design Guidelines
Louver Feature Design Guide
Minimum distance between louver feature and bending edge is maintained to avoid metal deformation.
(P1) Distance between Two lowers on Shorter Edge = 5 mm (P2) Distance between Two lowers on Longer Edge = 8 mm