14
Stick with HSS tooling or switch to carbide for aluminum? Split shop on this one.
I work in a job shop where half the guys swear by HSS for aluminum. Say it's cheaper, easier to sharpen. The other half run carbide inserts, claim they get better surface finish and longer runs between changes. I got stuck in the middle last week on a 200 part job. Tried HSS first. Got good results but had to stop and touch up tools after 30 parts. Carbide cut faster but chipped on a deep pocket. What side do you lean toward for production aluminum work?
3 comments
Log in to join the discussion
Log In3 Comments
pat_stone12d ago
Take sean_green44's variable helix idea and push it further for aluminum specifically. A 3-flute variable helix carbide endmill with a good chipbreaker geometry is a beast in 6061 because the irregular flute spacing breaks up harmonics, and those three flutes let you run faster feed rates than a two flute without sacrificing chip evacuation. For that deep pocket that chipped your standard carbide, try a rougher style with a variable helix and a 45 degree helix angle - it pushes chips up and out way better than a standard 30 degree helix. Pair that with a .005 IPT chip load and you'll see that little figure six chip formation without the chatter or chip packing. Test it on a scrap block first to dial in the rpm, but I've seen those tools run 200 parts without a single tool change on 6061.
5
king.eric12d ago
Take a closer look at that variable helix idea for deep pockets though... they're great for chatter in steel but in aluminum they can actually cause more problems with chip evacuation. The alternating flutes can trap chips in a deep slot. For that pocket you might've been better off with a three flute carbide rougher, gives you more chip room and still cuts way faster than HSS. Honestly sounds like your feeds and speeds were off on the carbide more than the tool itself. I'd try a standard two flute carbide with a good chipbreaker for that 6061, run it at 10k rpm and push the feed till you see those little figure six chips coming off nice.
4
Man, I heard a guy once say it's all about the alloy and what you're doing. For a 200 part run on plain 6061 I'd lean carbide all day, but for that deep pocket work you might need a rougher geometry. Ever try a variable helix carbide endmill? They handle the chatter way better than standard stuff.
3