Identify carbide parting insert?

[Jim Wilkins]

Since my lathe is old and worn carbide tends to chip easily on it. Today I
found a used parting holder and some Teledyne MP91M carbide inserts that I'd
like to learn about. The damaged label appears to show MP91M and T?B?TN-21?4
and the inserts are inked MP91M, the holder has no markings and may not even
be right for them, they seem to fit snugly without bottoming in the slot.
TIA

[Bob La Londe]

Post by Jim Wilkins
Since my lathe is old and worn carbide tends to chip easily on it. Today
I found a used parting holder and some Teledyne MP91M carbide inserts
that I'd like to learn about. The damaged label appears to show MP91M
and T?B?TN-21?4 and the inserts are inked MP91M, the holder has no
markings and may not even be right for them, they seem to fit snugly
without bottoming in the slot.
TIA

Weird. The only MP91M I found look a lot like the TDEX or SEHT used
mostly in face mills.

Oh, I also found one that looks like its for a shoulder mill.

[Bob La Londe]

Post by Jim Wilkins
Since my lathe is old and worn carbide tends to chip easily on it.
Today I found a used parting holder and some Teledyne MP91M carbide
inserts that I'd like to learn about. The damaged label appears to
show MP91M and T?B?TN-21?4 and the inserts are inked MP91M, the holder
has no markings and may not even be right for them, they seem to fit
snugly without bottoming in the slot.
TIA

Weird.  The only MP91M I found look a lot like the TDEX or SEHT used
mostly in face mills.
Oh, I also found one that looks like its for a shoulder mill.

Oh, here is one that's a parting insert. Looks like its from Stellram.
Now to just figure out if they make the size you need.

https://www.ebay.com/itm/186261864314?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1woCLvQvbRYeGTmhRsksReg23&norover=1&mkevt=1&mkrid=711-213727-13078-0&mkcid=2&itemid=186261864314&targetid=4580909052765420&device=c&mktype=&googleloc=&poi=&campaignid=603247545&mkgroupid=1236951576251627&rlsatarget=pla-4580909052765420&abcId=9316119&merchantid=51291&msclkid=f64af2bbb3b2192c44f9949154a6058f

[David Billington]

Post by Jim Wilkins
Since my lathe is old and worn carbide tends to chip easily on it.
Today I found a used parting holder and some Teledyne MP91M carbide
inserts that I'd like to learn about. The damaged label appears to
show MP91M and T?B?TN-21?4 and the inserts are inked MP91M, the
holder has no markings and may not even be right for them, they seem
to fit snugly without bottoming in the slot.
TIA

Weird.  The only MP91M I found look a lot like the TDEX or SEHT used
mostly in face mills.
Oh, I also found one that looks like its for a shoulder mill.

Oh, here is one that's a parting insert.  Looks like its from
Stellram. Now to just figure out if they make the size you need.
https://www.ebay.com/itm/186261864314?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1woCLvQvbRYeGTmhRsksReg23&norover=1&mkevt=1&mkrid=711-213727-13078-0&mkcid=2&itemid=186261864314&targetid=4580909052765420&device=c&mktype=&googleloc=&poi=&campaignid=603247545&mkgroupid=1236951576251627&rlsatarget=pla-4580909052765420&abcId=9316119&merchantid=51291&msclkid=f64af2bbb3b2192c44f9949154a6058f

Bob,

In case you weren't aware of it, you only the URL up to the question
mark like https://www.ebay.com/itm/186261864314 .

[Snag]

Oh, here is one that's a parting insert.  Looks like its from Stellram.
Now to just figure out if they make the size you need.

That insert looks just like the ones for my Shars holder . The holder
is a Shars P3W x 3/4 , number on the container is 202-9578 . The insert
package is numbered 404-0416 , might be the Shars part number . They are
1/8 thick , .562 long and .311 wide at the widest point .

Snag
"They may take our lives but
they'll never take our freedom."
William Wallace

[Jim Wilkins]

"Snag" wrote in message news:v0f325$3eot8$***@dont-email.me...

That insert looks just like the ones for my Shars holder . The holder
is a Shars P3W x 3/4 , number on the container is 202-9578 . The insert
package is numbered 404-0416 , might be the Shars part number . They are
1/8 thick , .562 long and .311 wide at the widest point .
Snag

-----------------------------------------
Thanks, the picture for 202-9578 shows the insert not bottomed in the slot,
same as mine, so the inserts should be correct for the holder, they were in
separate drawers of used tooling from auctions. The series is GTN which I
can now look up. Google is like magic; you have to know the right words.

Are there any special tricks to using them? With HSS I run below chatter
speed and keep the bottom of the groove constantly oiled with a needle
dropper bottle.

[Snag]

  That insert looks just like the ones for my Shars holder . The holder
is a Shars P3W x 3/4 , number on the container is 202-9578 . The insert
package is numbered 404-0416 , might be the Shars part number . They are
1/8 thick , .562 long and .311 wide at the widest point .
Snag
-----------------------------------------
Thanks, the picture for 202-9578 shows the insert not bottomed in the
slot, same as mine, so the inserts should be correct for the holder,
they were in separate drawers of used tooling from auctions. The series
is GTN which I can now look up. Google is like magic; you have to know
the right words.
Are there any special tricks to using them? With HSS I run below chatter
speed and keep the bottom of the groove constantly oiled with a needle
dropper bottle.

No special tricks that I've found . I run them the same way you do
HSS .

[Hul Tytus]

One key is to use a releif (sp?) angle of almost zero. If the cutoff tool wants to chatter or
dig into the work, it runs into itself.

Hul

Post by Snag
That insert looks just like the ones for my Shars holder . The holder
is a Shars P3W x 3/4 , number on the container is 202-9578 . The insert
package is numbered 404-0416 , might be the Shars part number . They are
1/8 thick , .562 long and .311 wide at the widest point .
Snag
-----------------------------------------
Thanks, the picture for 202-9578 shows the insert not bottomed in the slot,
same as mine, so the inserts should be correct for the holder, they were in
separate drawers of used tooling from auctions. The series is GTN which I
can now look up. Google is like magic; you have to know the right words.
Are there any special tricks to using them? With HSS I run below chatter
speed and keep the bottom of the groove constantly oiled with a needle
dropper bottle.

[Jim Wilkins]

"Hul Tytus" wrote in message news:v162mm$jdo$***@reader1.panix.com...
One key is to use a releif (sp?) angle of almost zero. If the cutoff tool
wants to chatter or
dig into the work, it runs into itself.
Hul
--------------------
Thanks. I hand-ground too much front relief angle on the HSS bit, then
reduced it at the tip until satisfactory. It looks to be about 1-1/2
degrees.

I bought the used GTN-2 parting tool to see if it would cut through the case
hardening on scrap cutoffs of hydraulic cylinder rod so it could be cut on a
bandsaw.