Favourite insert for best finish parting aluminium?

Fairly new to lathe work at our shop and currently using a Kyocera GMM3020-MT - zero radius insert for parting off in a standard 2 axis lathe - 6082/6061 aluminium.

Most parts we make have no requirement for surface finish on the parted side but we have some work that needs to be as good as possible and our parting tool isnt delivering here - plenty of time has been spent experimenting with speed/feed and going back in to take a finishing pass which has improved things but still not acceptable.

Parts are around 40mm dia, 30mm through hole and 5mm thick.

What are your go-to inserts for parting aluminium if you are looking for best face finish possible? (Dont mind buying a new holder) - Rad or no radius? We are adding a little back-chamfer to prevent too much 'tit' being left on the part so dont want that to get worse.

Thanks! Rick

Getting a nice finish when cutting off aluminum can be tricky. It can depend a lot on the batch of material. I use Tungaloy 2 mm wide inserts for most of my cutting off. For non-ferrous, I use their DGS2-020 inserts. That is a flat front with .2 mm rad. They offer a variety of lead angles and corner rads, but I would stick with the flat front and .2 mm rad if surface finish is what you're after. I recently noticed that they have another style specifically for non-ferrous and titanium that they claim "delivers fine surface finish". That would be a DGG style. I haven't tried it out, but it may be worth a call to your local Tungaloy representative. As always, a good supply of coolant is important. It might be worth getting one of the coolant-through holders to make sure coolant is getting to where it needs to be. Just keep in mind that this could all be for nothing because you got an odd batch of material that just won't give a nice finish when cutting off.

Well, I never use zero rake inserts, but if you are taking a clean-up pass, you nix that issue anyhow.
(re: surface finish)

I would recommend that you get an insert with a corner rad and stick with your clean-up pass.

I didn't follow your train of thought about the corner chamfer and tit correlation, but that's OK....
The tit situation will improve with a 12* insert. (or even 18*)


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