Surfacing for metals?

I’m curious if anyone has a recommendation for a 1"+ surfacing mill that is rated for aluminum. All I’m seeing online are spoilboard surfacing mills that are only recommended for wood.

They will work with aluminum also, YMMV depending on the grade of aluminum,
A little spritz of wd-40, or wipe the surface with candle wax before cutting to minimize the aluminum from sticking to the cutter.


Thank you, I appreciate the advice!

The carbide insertable surfacing endmills can be used on surfacing aluminum. They call them all spoilboard surfacing bits or cutters. Just make sure to purchase the one that has replaceable inserts because you will find out fast how frustrating it is to spend the money on a surfacing bit with fixed inserts and then they go bad pretty fast and you have to replace the whole thing.

The main thing you need to keep in mind with running aluminum is to keep it as cool as possible and to make sure to have a way to remove chips away from the cut. Aluminum gets gummy when it gets hot and tends to melt into the surrounding aluminum and even melt to the endmill.

You might spend a bit more money for an insertable surfacing endmill and even more on replacement inserts, but in the long run, it will be worth it and more cost effective. Each insert has 4 sides to cut with. So, 4 times the cutting edges.

I appreciate the advice! I do have a compressed air nozzle aimed at the end mill at 120psi and I spray wd40 during finish cuts. That’s a good tip on the replacable inserts. I just ordered one with a few packs of replacements. I’ve been cutting quite a bit of aluminum, but haven’t attempted a 1" cut surface cut yet. For what I’m doing, I only need 6 thou, so I would imagine the surfacing cutter can do that in a single pass.

I have ran bigger CNC machines that run 4" and 6" surfacing heads. These things are beasts. The wd40 may not be necessary for cutting aluminum, but if you dont mind the mess afterwards and it seems to be working for you better, then by all means, use it. Your air is sufficient. I had purchased the locked cutter surfacing bit and am pissed at how fast it burnt up, but I learned. One of the surfacing bits I was looking at has 4 inserts on it, two to the side that cut bottom and side cuts and 2 on the bottom that cut downwards if I need to plunge a little bit during cut. Sometimes it is just hard to bite that bullet and spend the $50 for the cutter and the extra $20+ for the extra inserts. I will be purchasing a replacement of my crappy cutter for one of these surfacing bits and never look back.

You got this with your aluminum cutting. Good luck.

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Oh wow. Yeah when I was in my twenties I got my first job doing cad work for a rail road parts supplier inputting old hand drawn drawings from the 1920s into solidworks. The parts were what’s called a frog insert. It’s this gigantic Manganese Steel casting that sits under the rails at points where the rails cross over each other. And after being cut on the cnc, it’s explosive hardened. Meaning they pack the top of it with plastique explosives and detonate it to compress the top of the steel lol

Anyway, that cnc was the size of a house. 20 years ago I was told the 6" cutter was $12,000. My first tool path I sent to the machine operator had my blood pressure sky high. Then watching that thing cut through a massive steel block like it was butter… I was hooked lol Those frog inserts come in several sizes, but the bigger ones are about 16’ long.