Bare Metal Finishes for your Sheet Metal Parts & Enclosures

Every week, Team Protocase is bringing you a Proto Tech Tip video, where we’ll give an informative look at a particular aspect of sheet metal fabrication and CNC Machining.

This week, Cody from our Engineering & Design Services team the three options we currently offer for bare-metal finishes. If you prefer to not opt for powdercoat paint for your custom enclosures or parts, this is a must watch!

Watch the full video below – or, if you’d prefer to read Cody’s Proto Tech Tip, we’ve got the full transcription below.

Be sure to subscribe to Protocase’s YouTube channel so you don’t miss a single Proto Tech Tip!

Hey everybody, welcome back for another Proto Tech Tip. Today we’re gonna talk about some bare metal finishes that Protocase offers for your closures or parts. Many engineers and designers will often choose powdercoat as their finish for the parts this is because it leaves it with a nice vibrant professional look. But what if you don’t want to have your parts painted? Protocase currently offers three options for bare metal finishes. These are grained finish, vibratory finish and no finish.

If you choose to, you can receive your part with no finish apply to it at all. This is typically referred to as no finish. In that case your part would still go through a deburring process after it has been laser-cut. Otherwise there is no additional finish applied to the part. This means that there will be swirl marks, scratches or blemishes produced during the manufacturing process.

No Finish is the best option economically for functional parts that will not be displayed.

The second bare metal finish that we offer is typically referred to as a grained finish and with grained finish the part is still deburred. Afterwards, the metal is brushed in a
specific direction to apply a linear grain. Grained finish produces a sleek minimalistic look. A few things to note about grained finish. For one the grain is typically applied while the parts are flat however, keep in mind if your parts have any kind of welding on them, after they are bent, we will have to reapply the grain and this is typically done by using our linear sander.

Keep in mind that if you have any type of geometry protruding from the surface of the part, the linear sander will have trouble getting into the corners. For a grained finish on a CNC machine part, we are only able to apply the grain to the exterior surfaces of the part. This is due to the previously mentioned constraints of the linear sander.

The last finish we’re going to talk about today is called our vibratory finish. To apply this finish, the parts are placed in a vibratory machine with an abrasive medium that smooths over the part. Vibratory finish puts a random pattern onto the part and rounds over the edges very well. It produces a look very similar to frosted glass, so compared to grained finish, a part where the vibratory finishing is typically much smoother.

The vibratory machine has a maximum part size of 10 inches in each dimension. The machine also has a minimum part size as well it needs to have at least 3 inches in length and at least 1 inch cross-sectional dimension.

So let’s talk about the finishes and graphics that you’re able to apply to your bare metal parts. So we can apply other chemical finishes such as chem film, passivation and anodizing,
depending on the metal that you’re using. We’ve done some Proto Tech Tips on these topics in the past, so check them out in the links below to learn more. If you have any kind of labeling, branding or any type of graphics that you want applied, you can choose either direct digital printing or silkscreen for your grained finish or vibratory finished parts, as long as it’s a flat surface. Check out Janelle’s digital print versus silkscreen Proto Tech Tip for a full rundown on these processes.

You’ll note that I didn’t include No Finish in my mention of graphics. This is because this finish is not a decorative finish in any way. Minor scratches blemishes and swirl marks are to be expected. We don’t typically advise placing graphics on the No Finish part because it is not aesthetically pleasing.

Check out our website if you would like more information and pictures showing the differences between these options. So thanks for watching this week’s Tech Tip video. I hope you found it useful. Be sure to drop any questions or comments in the comments section below and be sure to tune in next week for another Proto Tech Tip.