Using 8 sides of CNMG negative inserts

[Ridgerunner]

I use several CNMG inserts and can use all 8 corners of the negative inserts by using two different style holders. I use Kennametal and Ultra Dex Kenloc style tools with Aloris tool holders. In Ultra Dex nomenclature MCLNR 16-4d, the L is using the 80 degree tip of the insert. MCKNR 16-4d uses the 100 degree tip of the insert. Last R is for a right handed tool. 16 is 1 inch width/height tool. The 4 is for a 1/2 inch insert, like 432.... Scroll down in the links.
Unfortunately, the smallest size is 12 which is a 3/4 inch tool. After wearing down or chipping the 80 degree tip on 4 corners, the same inserts can be used on the remaining 4 sides in the 100 degree tool. In this configuration they make a wonderful facing tool.

Edit > title should have said 8 corners of insert.

[dian]

what does that do, face?

[pinstripe]

There are face mills that also use those edges.

[Ridgerunner]

what does that do, face?

In the 80 degree configuration it is a turn face tool. The insert like this is my main turning tool. I have taken .170 DOC and .015 IPR feed cuts with no problem. It does OK at facing. This picture sort of distorts the insert angles.



In the tool holder using the other 4 100 degree corners it is a terrific facing tool although it cannot face to a shoulder.

[JoeLee]

what does that do, face?

IN that particular holder, yes.

JL................

[JoeLee]

I use several CNMG inserts and can use all 8 corners of the negative inserts by using two different style holders. I use Kennametal and Ultra Dex Kenloc style tools with Aloris tool holders. In Ultra Dex nomenclature MCLNR 16-4d, the L is using the 80 degree tip of the insert. MCKNR 16-4d uses the 100 degree tip of the insert. Last R is for a right handed tool. 16 is 1 inch width/height tool. The 4 is for a 1/2 inch insert, like 432.... Scroll down in the links.
Unfortunately, the smallest size is 12 which is a 3/4 inch tool. After wearing down or chipping the 80 degree tip on 4 corners, the same inserts can be used on the remaining 4 sides in the 100 degree tool. In this configuration they make a wonderful facing tool.

Edit > title should have said 8 corners of insert.

I often wondered what I could do with those good sharp sides of that style insert when the insert is shot. I have a tool holder for that style insert, only I use the CNGP insert. Same thing but with dead sharp edge.

I've never bothered to look for a tool holder that holds the insert as shown in your picture because I didn't believe that they existed. Great for facing. Is there a holder that will hold the insert for turning??


JL................

[Ridgerunner]

I often wondered what I could do with those good sharp sides of that style insert when the insert is shot. I have a tool holder for that style insert, only I use the CNGP insert. Same thing but with dead sharp edge.

I've never bothered to look for a tool holder that holds the insert as shown in your picture because I didn't believe that they existed. Great for facing. Is there a holder that will hold the insert for turning??


JL................

Not to my knowledge. There should be. It is a shame to toss an insert with good corners on it.

[MattiJ]

Not to my knowledge. There should be. It is a shame to toss an insert with good corners on it.

There is. MCBNR

Or you could also use the MCMNN-100
https://www.amazon.com/Gaobey-40%C2%.../dp/B07NWJ2X4W

MCBNR style approach angle often breaks the chip even in nastiest materials as it crumbles against the workpiece.

[AWS]

For those using small CCMT, AR Warner makes a Holder that makes use of the otherwise unused tips of those inserts. I find it handy for roughing out inturrupted cuts, as who cares if an already blown insert fails partway through?

https://www.arwarnerco.com/Kit-4-1-4-inch-Turning-C-Right-Hand-Left-Hand-a-p/kit-04.htm

[MattiJ]

For those using small CCMT, AR Warner makes a Holder that makes use of the otherwise unused tips of those inserts. I find it handy for roughing out inturrupted cuts, as who cares if an already blown insert fails partway through?

https://www.arwarnerco.com/Kit-4-1-4...a-p/kit-04.htm

SCBCR for CCMT external turning. Got one as it was only few bucks from ebay/alibaba

[eKretz]

There are turning holders that use the 100° edge also. Can't turn to a 90° shoulder either, but they make good hogging inserts that way. Need a stout machine to really take advantage of them in that orientation though.

[mattthemuppet]

also work great in DIY fly cutters too!

[JoeLee]

Not to my knowledge. There should be. It is a shame to toss an insert with good corners on it.

That's what I always figured but even if there were a tool holder that would allow you to hold the insert so that "odd" edge could be used for turning, you wouldn't be able to get very close to a shoulder in either direction. Facing also has it's limitations if a shoulder is involved.

JL......................

[Ridgerunner]

That's what I always figured but even if there were a tool holder that would allow you to hold the insert so that "odd" edge could be used for turning, you wouldn't be able to get very close to a shoulder in either direction. Facing also has it's limitations if a shoulder is involved.

JL......................

True. It seems like 95 percent of the jobs I start I have to face off the part to set z zero and that is where the tool excels. I think the point is that it allows inserts that would otherwise get binned to be used completely, do a good job, and save money.

[JoeLee]

You know what you could do?..... The edge of that insert would be good for internal boring or turning, providing you were boring straight through. A tube for example. You could make a simple boring bar to hold it. You would also be limited on the size of the ID due to the thickness of that insert.
Or they could be used as a fly cutter, providing you have a way to mount it or a holder for it.

JL.....