Apple Silver Finish

Anyone know how they made the MacBook Pro, iPad’s, or Apple TV remote’s silver finish? Is that painted or can you treat metal a certain way to get it to look like that? I don’t know jack about how to finish metals but want to make a steel plate that will have a similar mattish silver finish like apple products.

Any tips?

Brushed aluminum.

It’s more than just brushed… I believe it’s anodized. Can anyone back up my assumption with data?

Im also pretty sure its anodized. Otherwise it suffer from corrsion, no?

Edit: Straight from the horses mouth.

As for your finish, i guess sand/beadblasting could work.

I stand corrected.

I did something similar to a piece of stainless steel a couple of months back, I bought a cheap abrasive blaster from Harbor Freight. Worked reasonably well for a small piece (table lamp)

You’ll have to experiment with what media you’re shooting out walnut shell, glass bead, or aluminum oxide. I had the best luck with fine grit aluminum oxide media.

If you’re using stainless it’s not going to look exactly like the Apple finish though because aluminum is a whiter metal.

This piece of metal will be a light switch plate and has to pass UL.
Is Anodized Aluminum OK for this application or should I stick with blasting an abrasive onto something like tungsten steel or iron? WOnder how I can prevent corrosision too…

If it were bare aluminum (even brushed) it would oxidize over time. The ano process helps prevent that.

So is it brushed then anodized or just straight up anodized? I’ve always wondered since the MBP is like virtually unscratchable.

It’s likely lightly sanded prior to anodizing. That would clean up any residual manufacturing blemishes. The anodizing process (hard anodizing anyway) leaves the surface very resistant to scratches. Anodizing is great, but it’s difficult to do well with welded parts.

You’ll need to verify this yourself (UL), but I think your switch plate will fall under “Enclosure”, which means the aluminum will only need to meet a certain thickness. The aluminum itself also doesn’t need to be protected against corrosion as it is considered as already having “inherent resistance to atmospheric corrosion”.

I don’t think it’s brushed (or sanded). Part of the anodizing process is an etch bath. If you leave it in the etching solution long enough, it will take off light machining marks. Sanding, or even media blasting, would knock off the very sharp edge that runs around the lip. I think these parts come straight off the machine into the anodizing process.

All the Apple stuff I have appears to have pretty standard Type II anodizing. The newer iPod Nanos appear to also have a bright dip step, which is what gives them that glossy look.

That’s right. I forgot about the etch bath finish…

The spec most plating houses use for anodizing is MIL-8625F

Type II is your standard anodizing, or “clear coat”.

Type III is your hard anodizing, or “hard coat”.

I’d guess that it’s a type II, as type III will often give a duller color (but have the aforementioned benefit of hardness…better than tool steel).

As for the texture, the anodizing house i typically work with tells me that whatever the finish you haver on the raw metal is the finish you will have on the anodized part. For the jobs I’ve done that’s held true for brushed and bead blasted surfaces.

I did some experiments in my school’s machine shop and my samples of 6061 Aluminum match my MacBook Pro after a round in the sandblaster. I’m not sure about the medium and I don’t have access to anodizing equipment, so I couldn’t test that, but it looks pretty close.

loughnane is right. What you send in to the anodizer is what you get back. If you send them a part that has mill marks, you will get back a part with mill marks. Actually, the process tends to highlight flaws in the surface. It will also slightly dull the existing finish. The Apple finish appears to be type II (sulphuric acid anodizing) class 1 (non dyed.) The metal will be bead blasted to a finish that is slightly shinier than the desired finish before anodizing.

Typically, the anodization process works best on machined aluminum (6061 is best) , it is much harder to get a good anodized finish from cast aluminum. I don’t have any experience with it, but I think this holds true for extruded aluminum as well. So if your part is going to be stamped from an extruded sheet of aluminum, I would speak with the finishing shop to maker sure there won’t be any problems.

Extrusions (typically 6063) anodize very well. That is probably how they are most often finished. The extrusions I get come back anodized super smooth.

This is a pretty old thread that got bumped, but the Apple stuff is absolutely media blasted in one form or another before it gets anodized. You can usually see the interior finish of that CNC part is much coarser: if hotlinking doesn’t work.