Guide / Sheet Metal Design

Sheet Metal Design Guide

Design principles for cost-effective sheet metal parts

Key Design Parameters

ParameterRecommendation
Minimum Bend Radius1x material thickness (aluminum), 1.5x (steel)
Minimum Hole Diameter1.2x material thickness
Minimum Slot Width1.5x material thickness
Minimum Flange Length3x material thickness + bend radius
Distance Hole to Bend2x material thickness + bend radius

Bend Allowance & K-Factor

Bend allowance = (0.017453 x Bend Angle) x (Inside Radius + K x Thickness)
K-factor for air bending: 0.33-0.42 depending on material and tooling.
Standard K-factor for steel: 0.42. For aluminum: 0.45.

Common Materials & Gauges

MaterialCommon GaugesMax Thickness (Bending)
Cold Rolled Steel (CRS)18ga - 11ga (1.2-3.0mm)6mm
Stainless Steel 30420ga - 14ga (0.9-2.0mm)4mm
Aluminum 606116ga - 8ga (1.5-4.0mm)8mm