Sheet metal is a common material used for CNC prototyping and machining. It may seem expensive at first, but it’s actually affordable when you consider the cost-per-part, which is often lower compared to other materials.
Today, you can find sheet metal used for everything from building slick cars to making roofs for homes and businesses for this reason. To learn more about whether sheet metal is expensive, keep reading.
Metal Fabrication Prices
Metal fabrication has dropped in price steadily over the years. Fabricators develop new processes and technology seemingly daily.
In fact, every aspect of the industry has decreased in price over the last decade. Now, new technologies lower overhead and increase production, reducing the overall cost of metal fabrication.
How Much Does It Cost to Make Sheet Metal?
Every sheet metal project is unique and therefore has a different price. However, it may help to look at the cost of sheet metal from a consumer perspective.
Most homeowners spend about $1,000 to $4,000 on sheet metal fabrication for a product such as metal roofing sheets. It’s a durable, versatile material with a range of applications for residential and commercial properties.
You’ll need to get an expert quote from an experienced fabricator who knows exactly how much your project will cost. However, the following may help to give you a general idea of the cost of a project.
The Cost of Sheet Metal Fabrication Prototyping
A small sheet metal prototyping project can cost as little as $300. Meanwhile, a large project could cost as much as $2,500. A typical sheet metal fabrication project may range from $754 to $1,624 for materials and labor, with an average cost of about $1,189.
The malleability of sheet metal lowers the length of the project. Also, sheet metal is relatively low maintenance, further reducing costs. These benefits can prove helpful over the course of a long-lasting project.
In either case, make sure you’re prepared to work out the costs. An extra long-term or comprehensive sheet metal project can cost much more.
Basic Principles of Sheet metal Fabrication
Sheet metal fabrication involves the process of forming parts from a metal sheet. A fabricator will start the process by designing 3D CAD files for a prototype.
Sheet metal is a material popular for low volume prototypes. It’s also cost-effective with high volume production runs.
Once you approve the CAD file, the fabricator will use a computer to turn the design into machine code. Now, a fabrication machine will precisely cut and form the final part.
They may also form the part by bending, cutting, stamping and punching a sheet of metal. For instance, they may use a sheet metal brake to bend and shape the metal.
Sheet metal parts have an excellent reputation for durability. As a result, they’re ideal for many end-use applications. However, there are several technical specifications it helps to know that may enable you to aid your fabricator in creating an effective design.
For instance, sheet metal parts must maintain a uniform thickness. You’ll also want to follow requirements and tolerances that ensure the parts fall closer to the design intent. This practice will also ensure that the fabricator cuts parts that serve your desired purpose effectively.
Even the simplest prototypes have complex technical specifications. The following information may help you get on the same page with your prototype designer.
Hole and Slot Dimensions
There’s a minimum distance that you should place holes and slots from a bend. This distance depends on material thickness, the bend radius and the diameter.
Holes and slots can become deformed when placed near a bend. With this in mind, you’ll want to make sure to place holes and slots at least two times the material’s thickness away from an edge. This practice will avoid a bulging effect.
Also, high-strength materials require larger diameters for holes and slots. You should not place the slots and holes too close together to the bends with this kind of material. You’ll want at least 1.5 times the thickness, or six times the thickness of the material, placed at a bend radius away from the bend.
Corner Fillets
Fillets round corners and remove sharp corners, making them easier to handle. Fabricators usually design them so that they’re one-half the thickness of the material.
Fillets are cost-effective. These relief cuts help parts fall closer to design intent. They also help to avoid overhangs or tearing. Tearing can occur when parts are made close to an edge.
Accordingly, bend areas must have at least 1/2 thickness. They must also have more length than the bend radius.
You’ll also want to make sure the overhangs are more prominent for thicker parts with a small bend radius. They may even need to equal the thickness of the material.
Forming Near Holes
Sometimes, a bend makes a hole to the bottom of a cutout. If so, it should equal the minimum flange length prescribed by the air bend force chart. During production, a punch press or laser cutting hole size should never have less size than that of the material thickness.
For a slot or hole less than 25mm in diameter, for example, the formula for the minimum distance from the hole to the center is 2t-2t. When a hole gets too close to a bend, the hole may become teardrop-shaped because of the bend.
Minimum Distance From Extruded Hole to Edge
Two extruded holes should have a minimum distance of at least three times the thickness of the sheet between the part edge. Inadequate spacing can lead to metal deformation or tearing. Accordingly, the minimum distance between two holes should equal six times the thickness of sheets.
It’s good practice to maintain a minimum distance between the two holes in metal designs of the same material. This practice will prevent the failure of the most extreme pressure applications in sheet metal press work that generates a lot of friction and heat. Extruding metal, for instance, is the most intense pressure application and generates lots of heat and friction during the production process.
K-Factor
Fabricators use the K-factor to calculate flat patterns as it is related to how much material gets stretched during bending. This is an important value to calculate correctly in CAD software.
The fabricator will need to use established guidelines in their CAD design. These guidelines help to determine the acceptable shape of the sheet metal.
Curls
Adding a hollow, circular roll to the edge of the sheet is called curling. Fabricators most often use curls to remove a sharp untreated edge.
Curling makes the end product safe for handling. However, it’s important that the curls are two times smaller than the material thickness.
The hole size should equal at least the radius of the curl plus material thickness from the curl feature. Meanwhile, a bend should be equal least six times the material thickness.
Kerf
A laser kerf is a small gap. It can range from 0.08 to 0.45mm, depending on material type and thickness. Your designer must leave a minimum distance of 1mm to 2mm between parts to avoid accidental crossover cutting.
Some sheets may have warped or slightly off sizing. It is also ideal for you to keep parts 2mm to 5mm away from the edge of the material for this reason.
Here, it’s important to design parts within the boundary of the sheet size. You don’t want to use the sheet edges as a border.
Choosing Materials and Finishing Sheet Metal Parts
Some materials are, by their nature, less likely to corrode. With this in mind, it tends to take fabricators less time and money to produce some speciality finishes.
Special materials and finishes require estimators to source out external quotes. A common finish is easier to use than a speciality finish, especially for powder coating
However, remember that you can’t use pre-plated materials such as galvannealed and galvanized metal if you need a welded seam. Also, going with speciality materials can add lead time and cost to the manufacturing process.
It will take longer to selecting materials and finishing materials. However, overall, it can prove cheaper and faster to produce a project with a speciality finish.
A sheet metal project could even require more than one type of material other than aluminium sheet metal. Ultimately, the metal you use will depend on what you need to accomplish your goal.
Ordering a Prototype Part
Whenever you send a quote, you’ll want to include a hardware bill of materials (BOM). You can produce a BOM using Word or Excel.
You can also include this information in the comments section of the request. When the fabricator has this information at hand, you don’t have to exchange a series of emails for getting the parts needed for the project.
You can even use a BOM to refer to specific finishes, materials, and other requirements. Having this information is important to ensure accuracy.
A BOM also enables fabricators to order all needed hardware so that they can complete your project as scheduled. What’s more, you won’t waste time figuring out how to communicate if you clearly define your needs.
It Helps to Have Flexibility
You may want specific dimensions for certain features. If so, you should include that information in your request for proposal (RFP).
In your RFP, you’ll want to aim for standardized sizes for punch-form features, such as bridge lances and embosses. If you don’t include this information in the original RFP, you might receive it if they must send back a proposal revision request. The process of standardizing sizes in this way can increase the time it takes to complete a project.
You should also consider any needed services, such as in-house tooling, in your original RFP. This kind of forethought reduces costs, time and delivery of materials. It can also reduce manufacturing time. Avoid Elaborate Design Elements for Sheet Metal Fabrication You may want or need extra-specific design elements.
These elements could include machined pockets and blind holes. However, these kinds of features could increase production costs. Take chamfered edges, for example. They can limit the chance that users will injure themselves.
Also, specialized design elements will most likely look great. However, aiming for simplicity is a good practice for the most basic type of parts you can buy. Adding features such as chamfers and blank holes could drive up costs and lead times on sheet metal parts.
Finding a Professional Fabricator
Sheet metal is an excellent building material for projects ranging from making a fence to creating products to constructing an industrial building. Remember, however, price isn’t everything. When you pay a slightly higher price for your metal project, the fabricator will most likely deliver a better quality result.
Of course, you want to find a professional sheet metal fabricator in your area. However, it’s important that they have the necessary skills and tools to get the job done quickly. What’s more, they must complete your project to a very high standard.
With this in mind, you might wonder, “How do I find a fabricator for sheet metal near me?” It’s a good idea to get quotes from several fabricators.
Also, you should check exactly what each quote includes. Reviewing quotes will help you to avoid unexpected fees for shipping or special treatments.
Finally, remember that most often, it’s worth paying a little a bit more to work with a sheet metal fabricator with an established reputation, such as Prototech Asia.
Learn More About Making Important Business Decisions
Now you know more about whether sheet metal is expensive. You’ve also learned more about the complex but interesting world of sheet metal prototype specifications. Sheet metal is a great material for designing and constructing projects, so it’s worth knowing more about the process.
We hope this blog post provided helpful information about the costs and specifications of sheet metal prototyping for entrepreneurs like yourself. If you want to learn even more helpful information, check out our business column for all the latest news from industry experts.