Insert Tool Holder Question

[ddickey]

Are there any advantages to a larger insert tool holder other than more rigidity?
I have an oversize tool holder that an accept 1" shank tools. I have a BXA post and looks like alignment (center of work) will not be a problem. Was looking at a holder on Ebay that accepts the TP.. 322 types inserts.
I'm trying to grind my own HSS tools but thought it might be worthwhile to have one of these.

 

[Doubleeboy]

Larger tool holders frequently make it harder to get into tight spaces, conversely they do usually give you more reach. I like the TPG insert, not the fanciest insert and does have its issues with stringy chips at certain speeds and feeds but its dirt cheap and very easy to touch up with a diamond hone or wheel. I find that tpg inserts can take a very small cut , less than .001" if you have a rigid set up and , sharp insert and good speed. Many other inserts will cut, then skip or build up edge, then the edge build up breaks, finish of part now looks like garbage. TPG is very good at not doing that IMO.

my comment about other carbide inserts skipping was in regards to very light cuts something the tpg does very well IMO.

 

[Jimsehr]

The tool holder should work fine. But before you buy it check price of inserts that fit it. For a home shop the Import insert tools and inserts are very low priced. google bangood and enter carbide . But it's nice to have a TPG 322 holder on hand. And you can get inserts for it off eBay. I think TPG stands for tool positive ground and 3 is insert size then 2 is thickness and last 2 is radius on the corner of insert.
Jimsehr

 

[Bob Korves]

With a 1" tool holder shank, you can cut a dovetail directly into the shank to go onto a BXA tool post. Check first to see how hard the shank material is, some are too hard to cut easily.

 

[ddickey]

I did that with the 1.25" shank used holder I bought. It didn't cut easily but wasn't that hard. After the fact I realized it was used only for facing.

 

[Bob Korves]

I think TPG stands for tool positive ground and 3 is insert size then 2 is thickness and last 2 is radius on the corner of insert.
Jimsehr

T stands for triangle. P stands for a 11 degree positive rake. G describes the hole in the insert. 3 stands for the inscribed circle of the insert, 3 means 3/8". The first 2 is the thickness of the insert in 16ths. The last 2 is the nose radius of the cutting corner in 64ths, in this case 1/32".
http://www.carbidedepot.com/formulas-insert-d.htm You, too, can look this up...

 

[Buffalo20]

I went with oversized tool holding blocks, because, usually the tools I wanted to use, started at either 5/8" or 3/4" shanks,. So by either machining the existing AXA blocks I had or the over sized blocks, I bought, I was able to go the series of carbide insert holders, with larger shanks, that I wanted. This was my only recourse, I really had, I had 2 larger tool shanks ground down to fit in a standard AXA block, (1/2"), but one of the shanks bent and the other, the shank broke. I gave up cutting the the shank of a $60 tool, and modified or bought a block that fit the shank, for less than $15.

I'm also not a fan of TPG inserts (work just okay in a couple of boring bars), yes, they are dirt cheap on the internet, but rarely is there any real quality(usually one step above compressed sand). When I first went to carbide inserts, i bought an Aloris AXA16N tool (desined for TPG inserts), unless I bought Valentine, Iscar or other Premium inserts, I got terrible results. I switched over to a TNMG or WNMG inserts, getting great results, inserts last longer, able to take deeper cuts and the finish was much better. I have not used the Aloris tool since then.

 

[Buffalo20]

T stands for triangle. P stands for a 11 degree positive rake. G describes the hole in the insert. 3 stands for the inscribed circle of the insert, 3 means 3/8". The first 2 is the thickness of the insert in 16ths. The last 2 is the nose radius of the cutting corner in 64ths, in this case 1/32".
http://www.carbidedepot.com/formulas-insert-d.htm You, too, can look this up...

I thought the G stood for ground, while a TPU is unground. There is no hole in a TPG insert

 

[Bob Korves]

I thought the G stood for ground, while a TPU is unground. There is no hole in a TPG insert

If there is no hole, there is no letter for hole/chip breaker. In that case the G would show the tolerance of the insert. See my link above...

 

[WoodBee]

I thought the G stood for ground, while a TPU is unground. There is no hole in a TPG insert

Shape, clearance angle, tolerance, hole
TPG -> T=triangle, P=11deg clearance, G="follow link", ommitted = no hole
As mentioned previously: see link!

It would also show "U" merely stands for different tolerance....