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Carbide insert holders for AXA tool post

phaxtris

(Ryan)
Premium Member
Premium Member
Ah, yes, that may be one point in favor. I think they are but it may not be a given in all cases. For example if they have positive rake maybe? wouldn't lend themselves to being supported inverted on flat of toolholder datum. Maybe someone who runs them can answer. Ultimately I guess its $/cutting corner. I find them to be very long lasting, but varies my work & materials.

TNMG has no rake/0 clearance angle to the insert, that's what the N stands for

I have one tool holder with a tnmg insert, the insert is very big, you would have to have one heck of a big boring bar to use that style of insert in it...unless they make a smaller tnmg than the one I have
 

PeterT

Ultra Member
Premium Member
TNMG has no rake/0 clearance angle to the insert, that's what the N stands for
I have one tool holder with a tnmg insert, the insert is very big, you would have to have one heck of a big boring bar to use that style of insert in it...unless they make a smaller tnmg than the one I have

Yeah sorry I just meant triangular inserts in general. Having said this they call these TNMG with positive rake & double sided, so who knows. I'm less familiar with them. I've seen them used in boring heads shanks but not in boring bars per se, due to size & geometry.

My boring bar reference was more of a consideration on the side of smaller CCMT (rhombic shaped) inserts. I use the exact inserts between my lathe tools & boring bars. BTW you can get pretty small min diameter boring tools for CCMT like the picture link I posted. I find the shank size range lends itself quite well to my size lathe, BXA type tool post.
 
FYI, here's the very small carbide tool holders that came in the box of odds and ends with my lathe. Look to be 1/4" shank?

If anyone can use these and about 7-8 extra TCMT inserts that look like they fit the holders in the Calgary area they are yours for the asking.
1648165374981.jpeg
 

phaxtris

(Ryan)
Premium Member
Premium Member
Yeah sorry I just meant triangular inserts in general. Having said this they call these TNMG with positive rake & double sided, so who knows. I'm less familiar with them. I've seen them used in boring heads shanks but not in boring bars per se, due to size & geometry.

My boring bar reference was more of a consideration on the side of smaller CCMT (rhombic shaped) inserts. I use the exact inserts between my lathe tools & boring bars. BTW you can get pretty small min diameter boring tools for CCMT like the picture link I posted. I find the shank size range lends itself quite well to my size lathe, BXA type tool post.

oh yea i agree triangle inserts would probably not be a great shape for a boring bar, i dont think i have seen a boring bar for triangle inserts, i do have a set for those itty bitty ccmt inserts tho..

but i dont think you can do everything with one shape, no matter what a guy is going to end up with a couple shape inserts, a decent sized turning ccmt is going to make a pretty big boring bar, and vise versa

FYI, here's the very small carbide tool holders that came in the box of odds and ends with my lathe. Look to be 1/4" shank?

If anyone can use these and about 7-8 extra TCMT inserts that look like they fit the holders in the Calgary area they are yours for the asking.
View attachment 22384

oh yes those are tiny, like 7x lathe size
 

RobinHood

Ultra Member
Premium Member
CNMG/CCMG & DNMG/DCMG are a stronger insert because of their geometry compared to a TNMG/TCMG insert. I run mostly the TNMG because of the 6 usable corners. I have offshore holders but use high quality inserts in them (ISCAR mostly). Makes all the difference.

Edit: 6 usable corners using the same tool holder for the TNMGs.
 
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