Tips and Best Practices for Common Sheet Metal Features
At Baillie Fabricating & Welding, we’ve seen nearly every type of sheet metal fabrication project imaginable. Over our decades of experience, our team has learned what works best and what can drive up costs when you’re adding common sheet metal features to your design.
We’ve put together this design for manufacturing (DFM) guide to help customers, engineers, and buyers understand some essential features in sheet metal design, as well as our tips on how to apply them most effectively.
Louvers
Louvers are vent-like openings that are punched or formed into sheet metal. We see them used most often for airflow, drainage, or ventilation.
Design Considerations
Louvers require specialized forming dies and tooling. A typical metal fabrication shop will have a limited selection of louver sizes and shapes, and adding louvers outside of those size options can sometimes be cost-prohibitive. Louvers are commonly produced using a punch press equipped with a forming die, though they can also be formed on a press brake with specialized tooling.
Our Recommendation
At Baillie Fabricating & Welding, we work closely with trusted vendors who can add louvers when your design requires them. Because available louver sizes can vary, we encourage customers to consult with us early in their design process. In some cases, using pre-made louvered panels can be an efficient, cost-effective alternative.
Slots
Slots are elongated holes that are usually laser cut or punched. They most often help with alignment and part assembly, but they can also be used for purposes such as drainage and ventilation.
Design Considerations
Slots can be created in a wide range of sizes, but the best choice is influenced by material thickness, fabrication process, and application. When using them with fasteners for alignment, it’s important to ensure the slot width can accommodate the fastener with enough clearance.
Our Recommendation
We often suggest slots as a simple, low-cost alternative to louvers for some purposes. We can incorporate slots into parts with our laser cutting services, avoiding the expense associated with louvers.
Tabs and Slot-and-Tab Assemblies
Tabs are common sheet metal features that are small extensions typically used to align or secure two parts during assembly. They are often used as part of a slot-and-tab system. This method can help improve alignment before welding.
Guidance on Tabs
Adding slot-and-tab to designs can reduce the need for fixtures and simplify welding. However, it must be built into the CAD model early to ensure proper fit.
Our Recommendation
Our team offers CAD assistance to help customers integrate slot-and-tab features to minimize welding time, which can be a significant cost driver on sheet metal fab projects.
Hems
A hem is a folded edge used to reinforce a sheet metal part, eliminate sharp edges, and improve overall safety and aesthetics.
Guidance on Hems
The most common hem styles are open hems and closed hems. Open hems have a visible gap and are easier to make, while closed hems are folded tightly flat against the surface for a cleaner edge.
Our Recommendation
Hems can be a good solution for sharp edges, often adding a professional finish to parts. We can advise whether an open or closed hem is best for your design based on factors like material thickness and application.
Hinges
Hinges enable movement between two connected parts, like a door or a cabinet hinge. There is a huge variety of hinge designs available in custom sheet metal fabrication.
Design Considerations
Some of our customers create complex custom hinges, while others request basic, off-the-shelf hinges for cost-efficiency. Material, load rating, lubrication needs, and application can all influence the best hinge choice.
Our Recommendation
It can be challenging to select a hinge due to the sheer variety available. Baillie Fabricating & Welding has experience with all types of hinges and can recommend the best option for your design once we understand your application.
Your Partner for DFM Insight
When you share your drawings and goals with us, we review the common sheet metal features you’ve included to ensure you’ve made choices that are manufacturable and efficient. Our team can recommend simple adjustments to minimize cost while maintaining performance.
Request a quote today to see how our Pennsylvania metal fabrication shop can help you with your next project!
