Optimizing Sheet Metal Designs: 5 Tips for Mechanical Engineers

Sheet metal fabrication is a staple of product development and mechanical engineering and is required in industry applications including aerospace, automotive, electronics, and consumer goods. Cost-effectiveness, performance, and productivity are more and more in demand, and the mechanical engineer is forced to look beyond fundamentals to create functional but manufacturability-enhanced, low-cost, and durable designs.

Whether building a new enclosure or creating intricate assemblies, optimizing sheet metal design with the help of Precision Sheet Metal Components Manufacturers is essential. What follows are five best practices mechanical engineers can apply to optimize sheet metal design processes, reduce errors, and attain superior outcomes.

1. Design for Manufacturability (DFM)

The only thread of commonality that runs through sheet metal design optimization is manufacturing design. I.e., parts designed to be simply and cheaply made by common fabrication methods such as bending, punching, laser cutting, or stamping.

Key Things to Remember:

• Don't over-engineer: Geometric detail is wonderful but typically will have to be engineered with special tooling or secondary operations, both of which are time- and cost-expensive.

• Minimum bend radii: Forming to minimum bend radii (typically equal to material thickness) avoids the need for special equipment and provides greater consistency in fabrication.

• Even wall thickness: More difficult to cut and form with uneven thickness. Even thickness provides even material handling and better results.

• Limit small details: Small tabs, holes, or detailed cutouts cannot be machined to a specific size and get distorted when bent or cut. Use the recommended minimum hole pitch and size indicated by the manufacturer.

By taking manufacturability issues in hand early on with manufacturing partners and DFM rule checking, you will not need to make major redesigns to make your designs production-capable.

2. Bent Relief and Tolerances

Bending is a simple sheet metal shaping process. But if it's poorly planned, then it happens to lead to tearing, warping, or wonky pieces when finished. Incorporating proper bend reliefs and tolerances will make your parts producible and functional.

Best Practices:

Use bend reliefs at material locations where material would fracture or elongate when bending. Bend-relieving notches are tiny relieving notches used to relieve stresses and obtain neater bends.

• Specify minimum flange size: The majority of fabrication shops will have a minimum flange size to ensure bend accuracy. This will be tooling- and material-thickness dependent.

• Form consistent bend directions: Restrict reorientations to speed production and improve accuracy.

• Reasonable tolerances: Don't over-spec. Tight tolerances are expensive to make and are reserved for critical areas. For standard features, ±0.005"" to ±0.010"" will suffice.

Understanding how material is going to behave when stressed and what you are going to do with it in advance will save you from spending enormous sums of money on futile designing.

3. Choose the right Material

Material choice has a significant effect on the cost, performance, and manufacturability of your sheet metal component. Each material possesses some combination of attributes—i.e., strength, corrosion resistance, conductivity, and formability—that are best applied to specific applications.

Common Sheet Metal Materials:

• Mild Steel: Inexpensive and simple to bend, typical use.

• Stainless Steel: Durable and corrosion-resistant, but difficult to cut and bend.

• Aluminium: It resists corrosion and is light, ideal for electronics and airplanes.

• Brass and Copper: Suitable to work with electricity, but costly.

Suggestion:

• Correlate material use with purpose and surroundings. Such as stainless steel in outdoor enclosures or harsh environments.

• Consider material thickness when creating the initial design phases. The thicker metals will be difficult to bend without warping and may need special equipment.

• Maintain inventory levels so that production is not delayed or waiting on settlement of special orders.

In making your best material for your application, you have performance at the point of cost and manufacturing effort.

4. Use Standard Elements and Fastening Means

One of the easiest ways of refining sheet metal designs is through the use of standard parts and fasteners. Unique features complicate manufacturing, and the use of standard patterns and parts therefore enhances compatibility, facilitates easy assembly, and is cost-effective.

Recommended Practices:

• Self-clinching fasteners (PEMs): They are incorporated in sheet metal during manufacturing and form permanent threads without tapping or welding.

• Tabs and slots: Using these at assembly locations reduces fixtures and makes the welding or assembling process easier.

• Tooling-friendly characteristics: Punching out round holes is easier than punching out oval or square holes. Employ the same size and same type of hole whenever possible.

• Reduce welding usage to an absolute minimum: Although welding produces very strong welds, it is expensive and time-consuming. Use rivets, fasteners, or folds where possible.

Also incorporate standard hole patterns to fit electronic parts, fans, or panels for most devices' compatibility.

5. CAD Tools and Simulation

Sheet metal design is now revolutionized by CAD tools. The best software like SolidWorks, Autodesk Inventor, or Siemens NX, all have sophisticated sheet metal modules that include unfolding, bend allowance, and manufacturability check.

Optimizing with CAD:

Employ sheet metal-specific attributes rather than generic extrusions or cuts. The properties help to provide correct flat patterns and add bend allowances automatically.

• Process simulation for bending: Observe the way the part shapes out and make sure there are no interferences or issues when designing.

• Generate accurate flat patterns: The flat projections are required for laser cutting and CNC cutting. Make sure your software accurately accounts for bend deductions.

• Remote work: Send designs to manufacturers in a format like DXF, STEP, or native CAD file format for real-time and accurate quoting or tooling.

Send them over at the start of the design workflow so problems are identified prior to reaching the shop floor, which saves time and rework.

Conclusion

Metal sheet design is a science and an art. It's easy to get bogged down with worries over pure function or form, but seasoned mechanical designers know that optimal optimization is actually a balancing of cost, manufacturability, and performance. By adhering to these five fundamental rules described above—design for manufacturability, abiding by bend tolerances, choosing appropriate materials, using standard features, and using CAD tools—you can significantly enhance the success rate of your sheet metal projects.

Whether you're creating small gadgets or big enclosures, smart, cost-saving sheet metal design is the secret to efficient manufacture, increased strength, and minimized cost. Start applying these concepts on your next job—and make sheet metal designs not only perform but thrive.

Also Read: Automotive Sheet Metal Fabrication: Different Techniques and Materials