Parting off alluminium

Getting frustrated when parting off aluminium.

I use a Glanze parting off tool with carbide tip, however the problem I have is half way through the alloy welds itself to the tip and if I am not quick enough the lathe jams and buggers the tip and the holder

Any suggestion as to how to avoid this?

WD40 or similar liberally applied.

Nigel B

Paraffin works for me

Some aluminium can be stickier than other grades, as Nigel B suggests, WD40 or parafin, you can also tell things not happy by watching the award and listening, back the tool out, clear the tip and get back in.

Some aluminium can be stickier than other grades, as Nigel B suggests, WD40 or parafin, you can also tell things not happy by watching the swarf and listening, back the tool out, clear the tip and get back in.

Edited By Howi on 06/01/2017 16:52:54

Plus one for plenty of lube. I use paraffin of neat soluble oil.

For parting off aluminium alloy with insert tooling I always use flood coolant (soluble oil) and a decent feedrate, at least 6 thou/rev. The topslide and saddle are locked.

I don't have a Glanze parting holder, but the Glanze boring bars I use are fine, once the supplied inserts were binned and replaced by a decent industrial brand.

Andrew

Let the material and tip cool now and again which can also be done via a slower feed and speed variations.

Micropolished inserts are almost bound to help too.

John

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Ok, so some coolant will help.

Andrew, you mention using better inserts, which ones

John, Micropolished inserts???

as others have said ally can be sticky, and also has a low melting point, and even though you shouldn't get to the point of melting, you can get it to a point where it more of a soft solid, so I use a good flow of coolant, and light pressure backing out to clear the swarf regulally

Aluminium is very abrasive stuff so they produce various micropolished tips - the coating can't get rubbed of those. The coated tips start to deteriorate before the coating is completely worn off as well.

Ordinary turning tips are available micropolished. So far I haven't found any for parting off. Somebody some where may have them though. My usual source ( ATP ) has turning tips like this but none for parting off. Just general or stainless.

John

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Korloy actually sell an uncoated parting insert in grade H01. This is sold as being suitable for aluminium and other nonferrous metals. I have some that I bought from Cutwel but tantalisingly I haven't been able to test them here in my armchair workshop. AFAIK, these are the GTN-style inserts that are compatible with many other holders.

These are the uncoated (for loominum) and yellow coated (for steel) inserts, side by side. Note that the uncoated inserts are not polished.....

Murray

If you use the MGEH type grooving and parting holders then APT do an insert for Ali that fits them. I have taken to using this holder more than the GTN holder (Glanze etc) for parting since one arrived from ARC Euro.

Edited By JasonB on 06/01/2017 19:53:01

I was just looking a the Chronos site and Glanze also do something similar. Is this system better than the blade type?

They seem more rigid when you start using them sideways for profiling or widening a groove but generally won't go as deep as the blade type and that depth is dependant on shank size so you are limited on max dia you can part off.

I've used assorted brands over the years but I've settled on Korloy inserts from Cutwel. I use CCMT inserts for everything except aluminium, where I use CCGT polished inserts.

For parting I use an Interstate blade system and whatever insert came with it. I use the same insert for all materials, including aluminium. Flood coolant is used for all materials except those which are short chipping, ie, brass and cast iron. The single most important factor is feedrate. Below 4 thou/rev the insert chatters. At higher feedrates 6-8 thou/rev the chips curl properly, are folded inwards and break into relatively short chips. The system seems to work fine on deep grooving too:

Andrew

Do these fit any of the 25mm / 1" deep holders that are available Jason?

I can only see one polished insert on there for grooving / profiling - 6mm wide. The others are just uncoated

John

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No

Yes think you are right they are uncoated but geometry for ali

May work better if you also increase the speed.