Routing Aluminum

You can rout aluminum with the right bits if you're careful, but the wise course may be to bring this work to a specialty shop. December 28, 2014

Question (WOODWEB Member) :
I need to cerate some 1 1/4" x 1 1/4" finished openings in 1/8" anodized aluminum stock. I'm assuming that since I can cut aluminum with a carbide saw blade that I can rout it with a carbide router bit. I'm sure you can only remove very small amounts in each pass. Does anyone have experience with doing this or any tips you can pass on to maybe save me from learning the hard way?

Forum Responses
(Architectural Woodworking Forum)
From contributor G:
Use the slowest speed on the router you can. Unless the aluminum is very soft don't expect the bits to last too long. If somehow you could cool the bit it would last much longer. Even an air stream would be better than nothing. Liquid cooling would be best, but inconvenient at best.

From Contributor S:
Use bits made for the purpose (such as Onsrud) not wood bits. They are available from professional bit suppliers, not retail hardware stores.

From contributor M:
Don't waste your time, or the expense of high quality bits that you will mess up with a couple of uncontrolled passes. Take it to a machine shop with a vertical mill (common machine) and get it properly done. You might even get away without scratching the finish.

From the original questioner:
Thanks for the replies. I think I will take Contributor M's advice and take it to a machine shop. After all it's an extra, requested by and being paid for by the client. It makes no sense for me to risk damaging the aluminum pieces.

From contributor L:
We machine aluminum for a machine shop when the parts are too big for their machines. They provide the metal working carbide bits. There are many grades of aluminum. The worst ones to machine are sticky and require coolant. Most can be run dry. Typical feeds and rotations aren't that much different than for wood. The machine shop gives us the feed info. Bits last a long time. We usually fixture the work rather than relying on the vacuum table.

From contributor C:
Find a shop with a water jet machine. No scuffs, no discoloration on the anodizing, and dead accurate.

From contributor H:
You posted it is an extra for a customer so you’d take it to a machine shop. I'd second that. If you want to cut aluminum for your own use it is not all that hard depending on the alloy. I use my work working machinery and have found that if I spray it with a lube it doesn't stick to the bits. There is wax for this purpose but however wrong I use WD40, it works. I have run parts over my jointer and through my planer and made cuts with my slider. I suppose it might be hard on the cutters.