Tangential Tool holder

[VicParticipant @vic]

How many of you that use one grind a slight radius on the toolbit and why. I find a sharp edge cuts fine and gives a good finish but just wondering what most other folks do.

[VicParticipant @vic]

[John HaineParticipant @johnhaine32865]

A slight radius can improve the finish but more importantly makes the edge less prone to chipping.

[Rik ShawParticipant @rikshaw]

I agree with John. Rather than grind though I use an abrasive stone and stone a small radius the full length of the toobit. Once done it need not be done again.

Rik

[Thor 🇳🇴Participant @thor]

Vic, I do as Rik, except I used a diamond hone to make the small radius, I also use the diamond hone on the newly ground edge.

Thor

[Ian Skeldon 2Participant @ianskeldon2]

I have seen tagential tool holders mentioned several times recently, can I ask exactly what is a tangential tool holder, where do you get them from what are the advantages/disadvantages of using one?

[Thor 🇳🇴Participant @thor]

Hi Ian,

Here is links to  home-made ones. The subject was discussed earlier here, here and here. It is very easy to grind the toolbit to correct angles, it cuts well and I use my home-made ones a lot.

Thor

Edited By Thor on 29/07/2018 17:26:23

[VicParticipant @vic]

Posted by Ian Skeldon 2 on 29/07/2018 16:56:51:

I have seen tagential tool holders mentioned several times recently, can I ask exactly what is a tangential tool holder, where do you get them from what are the advantages/disadvantages of using one?

Many people make their own or you can buy them from:

**LINK**

The advantages are that once you have the holder they are cheap to run using small pieces of HSS. They are also quick and easy to sharpen. You can also turn and face at the same setting. You can use carbide in them for tough materials.

The only downside I’ve come across is they don’t fit into some tight turning situations. I use insert tooling if space is tight.

[VicParticipant @vic]

This is one of mine, there are a couple more pics in my album.

[mechman48Participant @mechman48]

Posted by Thor on 29/07/2018 16:44:24:

Vic, I do as Rik, except I used a diamond hone to make the small radius, I also use the diamond hone on the newly ground edge.

Thor

​Same here, works a treat.

George

[VicParticipant @vic]

Thanks for all the replies, I’ll give it a try.

[Ian Skeldon 2Participant @ianskeldon2]

Thor and Vic thank you, very interesting. The actual item is not like the image I had in mind and looks very simple with muliple uses.

Thank you.

Ian

[VicParticipant @vic]

Another thing I like is quick height setting once you’ve made a jig for your lathe. Only takes a few seconds.

[Joseph Noci 1Participant @josephnoci1]

Maybe more pricey than the simple square HSS tangential bar holder, but these work very well, solid grip of the cutter- cutter cannot slip during interrupted cuts, and can cut right up to the shoulder/chuck, etc. The cutter and holder has a serrated or knurled section that prevents cutter slip downwards.

10 cutters have lasted me more than 20 years…

These are some of the cutter shapes – Thread cutting shapes also available.

Holders with cutters in place:

Joe

[DrDaveParticipant @drdave]

I thought that putting a radius on the corner of the tool was done to avoid having a sharp corner when turning a shoulder.

[mechman48Participant @mechman48]

Posted by DrDave on 29/07/2018 22:03:14:

I thought that putting a radius on the corner of the tool was done to avoid having a sharp corner when turning a shoulder.

That was one of the original trains of thought, turning to a sharp corner creates a fracture point. During my apprenticeship I was always told to put a slight radius on the tip for that reason, it also helps with the finish, doesn't leave record groove finish, depending on feeds & speeds of course, also if you're using a comparison plate to compare against.

George.

 

Edited By mechman48 on 30/07/2018 11:03:24

[VicParticipant @vic]

Interesting tool holder Joseph. I wonder if you can still get those toolbits though and at what price?!

[Joseph Noci 1Participant @josephnoci1]

Vic, the inserts are quite expensive – I recently purchased some thread profiled inserts for these holders and they were around 60Euro each – From Hoffman tooling in Germany. But, as I say, these last a very long time – very quick and easy to sharpen, and you taken just a smidgen off in the process. The threading inserts were a Komet product.

The length of the insert rear edge – where the clamp bites – is serrated – likewise the clamp, so they grip with no slip, sometimes a problem with the simpler clamped square bar in heavier or interrupted cuts. You can just see the serrations on the upper part of the left hand insert in the first image I pasted. I have six unused inserts left from 10 purchased 22 years ago..and I do use these a lot – they give a very nice finish.

Joe

[I.M. OUTAHEREParticipant @i-m-outahere]

On some designs you can also hold round HSS to do a large corner radius . I usuall put a small radius on the square tool so when i cut up to a shoulder it leaves a small radius in the corner .

[VicParticipant @vic]

Yes the commercial versions allow you to mount both round and square cutters. I have a broken carbide milling cutter I’ve used in mine to take the hard skin off cast iron.

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