5 Things Product Designers Should Know About Sheet Metal Prototyping

by | Jun 18, 2021 | Prototyping

The sheet metal fabrication industry is one of the largest industries in the world. In fact, its global market size was valued at USD 265 billion in 2018 and projected to have a CAGR of 5% from 2019 to 2025.

As a product designer, especially of consumer products, there’s a pretty darn good chance you know how valuable sheet metal prototype fabrication is in product development. Yet, you might be unsure about how sheet metals are fabricated or the best design practices for sheet metal structures.

This article covers all these and many more. It will present five things you should know about sheet metal prototyping before doing business with a third-party fabrication shop.

#1 Sheet Metals Must Satisfy a Thickness Requirement

Like many other product designers, have you been describing sheet metals as metals that exist in flat pieces?

You’re not entirely wrong, but there’s more to the definition than “flat pieces.” Sheet metals typically have their thickness ranging between 0.006 inches and 0.25 inches. You could describe metals thicker than 0.25 inches as “metal plates” and those thinner than 0.006 inches as “foils” or “leaf metals.”

#2 There Exist Many Different Sheet Metal Fabrication Processes

In sheet metal fabrication, the sheet metal worker usually starts with flat pieces of metals and transforms them into structures (or products) using different fabrication processes, such as:

  • Cutting
  • Deformation
  • Assembly

The Cutting Process

As the name suggests, the cutting process involves manipulating the sheet metal by creating cuts using special pieces of machinery, including CNC laser cutters, water jet cutters, and plasma cutters. (Related Post: Here are 5 Types of CNC Machines You Should Absolutely Know About)

The Deformation Process

Sheet metal deformation describes the process of changing the shape of the sheet metal by bending, stretching, and drawing. The process involves using specialized tools like press brakes and metal stamping presses.

A press brake allows you to bend sheet metals into different angles and shapes. In contrast, the metal stamping press (featuring a punch and a die) allows you to perform specific tasks like embossing, hemming, and drawing.


Assembly describes the process of joining different sheet metal parts together using fasteners or via welding. The welding process is the more common of the two, and you’ve got a wide range of welding techniques to choose from, including arc welding, electron beam welding, among others.

So let’s say you’re looking to fabricate and assemble two right-angle brackets. First off, you’ll have to create cuts and critical features (such as holes) on the flat sheet metal parts using a laser cutter, water jet cutter, or plasma cutter.

Next, place these sheets of metal between the punch and die of the press brake and bend till you achieve 90°. Finally, weld (or fasten) these parts together to form the desired custom metal fabrication prototype.

#3 Sheet Metal Prototype Fabrication Comes with Many Advantages

One of the biggest reasons sheet metal prototyping helps businesses is the guesswork it eliminates in manufacturing. These prototypes act as physical samples (or mock-up models) of your design concepts, allowing you to test the performance of your design and detect flaws long before manufacturing begins.

You might see the initial cost of sheet metal prototype fabrication as a downside. But you may be missing the bigger picture. Imagine how much more you’d have to spend if, say, you go all-in with manufacturing and end up with a whole batch of units with errors.

#4 Engineering Materials for Sheet Metal Prototype Fabrication

Pretty much all the common engineering materials are used in the form of sheets. Some of the metals include aluminum, stainless steel, copper, and magnesium, among others. The right choice typically depends on the end-use properties you hope to get and the requirements of your product.

You should opt for aluminum if your product requires a lightweight metal with high strength, thermal, and corrosion resistance. Stainless steel and copper are ideal if you’re looking for a mix of strength, machinability, and good surface finishes.

Magnesium sheet metals also offer high strength and durability, and they are lightweight (approximately two-thirds the density of aluminum). However, they are highly flammable and pose a significant risk to you during (and after) fabrication. You should steer clear of magnesium sheet metals unless it’s absolutely necessary. (Related Post: CNC Machining Magnesium: What are the Safety Concerns?)

#5 Best Design Practices for Sheet Metal Prototypes

The following design practices will help you reduce manufacturing costs and shorten lead times when fabricating sheet metal prototypes.

  1. Design holes with a diameter at least equal to the sheet metal thickness since it eliminates the chance of a tool breaking or getting damaged.
  2. Assign key tolerances only to features critical to your prototype’s functionality.
  3. Design bends to have a radius greater than (or equal to) the sheet metal thickness, as this will keep your design simple and much easier to fabricate.
  4. Keep all features at least four times the material thickness away from bend lines since closer features create difficulties during fabrication.
  5. Outsource the fabrication process to a top-tier fabrication shop with a track record of high-quality services.

Gensun Precision Machining has provided high-quality sheet metal rapid prototyping services to a wide variety of industries for nearly two decades. Our fabrication shops can help you create cost-effective sheet metal prototypes through a variety of processes, including laser cutting, prototype stamping, bending, and welding.

Learn more about our sheet metal fabrication services.

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