Carbide selection help

[mattthemuppet]

Yup, both ccgt09 and dcgt09 fit the same holder.

I'm sure this is a typo, but just to clarify you meant CCMT09 right?

for loose nut - xxGT inserts have a very sharp ground edge, with a bunch of top (back?) rake. They're originally for alu but i've found them to work well on steel - ymmv with your larger lathe. In my hands at least they give an awesome finish. xxMT have a molded edge, so are more robust but need more power/ rigidity than my lathe has to work properly - I'm sure they need more DOC and feed than I can give them, so I just use them for knocking rust off or interrupted cuts on steel. I'd get a pack of both inserts and double up on the holders.

The tip radius has something to do with DOC - smaller tip radii are for finishing as DOC is a function of tip radius, larger tip radii are for roughing. I've been happy with the middle one (-04 or .51, depending on nomenclature).

[MattiJ]

Matt, yes typo or brainfart on my side, haven't felt the sharpest for couple of days. Norovirus takes off the best edge of any man...

[loose nut]

I ordered a SCLCR holder and CCMT inserts, $22 CND total. I was going to get some of the CCGT inserts to try out but they are out of them right now. Hopefully they will restock. I will see how the CCMT inserts work and maybe order the other in the future. Thanks for the help.

[mattthemuppet]

I've bought from these guys before
http://www.ebay.com/itm/10pcs-Superi...UAAOSw8vZXMmmb

no guarantee yours will be the same, but it's not a lot of money to find out

[MattiJ]

I've bought from these guys before
http://www.ebay.com/itm/10pcs-Superi...UAAOSw8vZXMmmb

no guarantee yours will be the same, but it's not a lot of money to find out

Just don't expect to get anything genuine from zimi-hk or chinese ebay (insert) sellers in general.
Fakes or not they IMO still offer good value for money. For example to compare no-name inserts here:
http://www.ebay.de/itm/10-x-Wendepla...AAAOSwDk5UGBG-

[mattthemuppet]

for sure, no expectations there. As long as they cut well (and mine do at least) I don't really care whether they're genuine or not.

[dalee100]

I'm sure this is a typo, but just to clarify you meant CCMT09 right?

The tip radius has something to do with DOC - smaller tip radii are for finishing as DOC is a function of tip radius, larger tip radii are for roughing. I've been happy with the middle one (-04 or .51, depending on nomenclature).

Hi,

As a general starting rule for finishing pass with carbide insets. Your final pass DOC should be equal to the nose radius of the insert. Then adjust up or down from there as needed to achieve your goal.

A larger radius roughing insert can give as good or sometimes better finish than a small radius finishing insert. Just need to leave more meat for the finish. You quickly learn this when programing for CNC lathes. Extra tool changes for roughing to finish tools cost time and money. But this needs to be balanced against what the machine can actually do and requirements of the finished part.

Dalee