Thread: Milling Gummy Aluminum....

I have to machine some aluminum extrusions (an off-the-shelf Hammond electronics enclosure) of an unknown alloy. But, it is the gummiest, most awful stuff I've ever seen! Even a slow plunge cut raises a huge burr all around the edge of the hole. I'm using a brand-new 1/8" HSS 2-flute, 6000 RPM, 0.010" DOC, 10 IPM feed, with flood coolant. The cut yields an awful surface finish, with a high burr the full length of both sides of the cut. Going slower doesn't help, and going faster, or deeper, just breaks the tool in short order. How does one machine this stuff?

Regards,
Ray L.

lower the rpm , up your coolant concentration and don't plunge

Originally Posted by SCzEngrgGroup

I have to machine some aluminum extrusions (an off-the-shelf Hammond electronics enclosure) of an unknown alloy. But, it is the gummiest, most awful stuff I've ever seen! Even a slow plunge cut raises a huge burr all around the edge of the hole. I'm using a brand-new 1/8" HSS 2-flute, 6000 RPM, 0.010" DOC, 10 IPM feed, with flood coolant. The cut yields an awful surface finish, with a high burr the full length of both sides of the cut. Going slower doesn't help, and going faster, or deeper, just breaks the tool in short order. How does one machine this stuff?

Regards,
Ray L.

It's probably dead soft material, and if it is, you'll never get a good finish and it will ALWAYS leave a big burr. Are you climb cutting or conventional cutting? Uf you're conventional cutting, you're nut really cutting material, you're just pushing it out of the way.

I did find out it's 6063, obviously not heat-treated. I've never seen anything so awful to work with. I tried using a larger (1/2") end mill to make a hole, then use the smaller endmill peripheral cutting to do the finishing. The 1/2" endmill hit the material, ramped down about 0.020", and was then summarily destroyed - corners broken off, all cutting edges completely mangled. You'd think I was trying to machine granite! I've thrown in the towel, and will take it to be either water-jet or laser cut....

Regards,
Ray L.

SCzEngrgGroup

Most extrusion is 6063, I have never had any troubles with machining it, I cut it quite a lot, Holes ,Slots, Threading Etc & use the same speeds & feeds as for 6061

Micro 100 makes a single flute mill that I use to plunge cut extrusion. I can dig up the number tomorrow when I get to the shop if you want. I've put hundreds of holes in 6063 extrusion with them.

Derek