Design for Sheet Metal Fabrication Toolkit

Optimizing Part Design for Sheet Metal Fabrication

There are many design elements involved in creating parts for sheet metal fabrication—design for cost, quality, assembly, and manufacturability. Navigating that landscape can be challenging at times. At Protolabs, we provide automated design analysis on CAD models that highlights features in your part design that can be adjusted for manufacturability. It’s a great design resource right at your fingertips. To keep design advisories at a minimum and optimize part design, we created this helpful kit of sheet metal fabrication resources.

Designing Complex Features for Molded Parts

→ 8 Rules for Converting Solid 3D Designs to Flat Sheet Metal
→ The Basics of Bend Radii in Sheet Metal
→ Integrating Hardware into Sheet Metal Design
→ Working with Sheet Metal Tolerances
→ Designing Sheet Metal Notches, Tabs, and Slots

Navigating Critical Molding Advisories

→ Minimum Flange Lengths
→ Placing Features Near Bends
→ Bend Radius Out of Tooling Range
→ Hardware Insert and Sheet Stock Compatibility

Navigating Critical Sheet Metal Advisories

Minimum Flange Lengths

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Minimum flange lengths are required to hold a workpiece between the top and bottom die in the press brake. The necessary flange length for forming is dependent on material type, material thickness, and bend radius. Refer to the table below for length guidelines per Protolabs tooling requirements.

Additional design considerations:

• Choose a smaller internal bend radius.
• For alternative fabrication options, schedule a time to review your design with a sheet metal applications engineer.

Placing Features Near Bends

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Feature placement in sheet metal design unlocks complexity and part functionality, however as sheet metal stretches during forming, features can distort if placed too close to bends. Like minimum flange length, feature proximity to a bend is dependent on material type, material thickness, and bend radius. Refer to the table below for distance guidelines.

Additional design considerations:

• Choose a smaller internal radius.
• For alternative fabrication options, schedule a time to review your design with a sheet metal applications engineer.

Bend Radius Out of Tooling Range

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Protolabs provides a range of internal bend radius tooling options between 0.01 in. and 1 in.

Note: As Protolabs uses primarily air bending technology, the actual radius on a physical part may vary slightly from the tool used during forming.

*If lead time is a priority, consider one of these options in your part design

• For parts with internal radii greater than 1 inch, Protolabs will use a technique called “bump” forming (multiple tooling lines will be present).