T type cut-off tools

[Shopgeezer]

In my last order to KBC I included a T style cut-off tool, since I have wanted to try one. The tool that arrived with the order was a standard parallel sided tool. No T shape. After a few phone calls the nice rep at KBC informed me that I had the right tool, that was what they sold as a T type cut—off tool.

Except it wasn’t T shaped. It started to sound like a Monty Python skit (That parrot is dead. No it isn’t it’s sleeping). My T style tool was a T style tool except it isn’t T shaped.

So I throw myself at the feet of the forum, seeking enlightenment. The T tool in the Acklands catalog is T shaped as in the picture. Mine is not (I am holding it end on for the photo). Mine does have a different grind along the top however. Would it maybe wear into a T shape with use? I dither in confusion.

 

[Hopper]

Get your money back. It is not a T profile tool. Speak to the rep's supervisor if you have to.
I bought a T parting tool from Eccentric Engineering and it is very definitely T shaped as shown in your first posted pic. They are commonly used on automated lathes etc in production. Nothing at all exotic about them.

 

[kwoodhands]

In my last order to KBC I included a T style cut-off tool, since I have wanted to try one. The tool that arrived with the order was a standard parallel sided tool. No T shape. After a few phone calls the nice rep at KBC informed me that I had the right tool, that was what they sold as a T type cut—off tool.

Except it wasn’t T shaped. It started to sound like a Monty Python skit (That parrot is dead. No it isn’t it’s sleeping). My T style tool was a T style tool except it isn’t T shaped.

So I throw myself at the feet of the forum, seeking enlightenment. The T tool in the Acklands catalog is T shaped as in the picture. Mine is not (I am holding it end on for the photo). Mine does have a different grind along the top however. Would it maybe wear into a T shape with use? I dither in confusion.

Mike the edges to see if one edge is thicker than the other. The T shape is hardly noticeable but the extra thickness on the top edge helps in parting off.
Tough to see but the second photo appears that the T is on the bottom . I have one type of parting tool that is parallel but the top is an upside down V shape. Another words the top is beveled down on each side of the centerline.

mike

 

[trlvn]

My KBC catalogue happened to be beside me. Looks like you got the KBC-brand "T-Shaped Cut-off Blade". Neither the catalogue or the web site shows the cross-section of the blade but I guess they mean it is tapered rather than a simple rectangle. As you've seen, it is clearly not the shape of a capital "T".

KBC also carries cutoff blades by Micro 100, eg:

https://www.kbctools.ca/itemdetail/1-428-T102

These have carbide tips brazed on and are clearly an actual "T" shape. Unfortunately, they seem to be sold in packs of 5 blades so are quite a bit more spendy.

BTW, do you have a cutoff-off tool holder with the groove for the "T"? I'm not sure how well a regular holder would do with "T" shape blades?

Craig

 

[Shopgeezer]

I haven’t found a specific “T” shaped holder in my usual supplier web sites. I have one holder I think would work ok which is why I ordered this blade.

And Mike, the top and bottom of the blade measure up the same, but there is something different going on along the top edge. This is supposed to be a cobalt blade. Maybe the top edge has been plated to make it harder?

 

[XD351]

I use a t style cut off tool supplied by eccentric tools
and it comes with a dedicatedly toolholder , the toolbits are U.S made and you can definitely see the t shape

 

[Mac McCaskie]

I have pretty much the same concerns with a 1/16" "P" style cutoff blade (about $8 US) I got a bit ago. Got to looking at it and it has a very slight concave groove just under what appears to be a honed top edge, but otherwise top and bottom thickness are very similar, no noticeable taper.

Anyway, I was googling and found other blades for $26 US (www.travers.com) and $45 US (www.carbideanddiamondtooling.com) with pic's of very noticeable T shapes.

What is the consensus with the more spendy blades? Is it worth the extra cost, I can afford it but don't need any more Ginsu knives.

 

[jack620]

What is the consensus with the more spendy blades? Is it worth the extra cost...

I think so. I also have the US made cobalt T blade supplied by Eccentric Engineering. It's superb. Even cuts titanium nicely if you give it a quick touch up on the grinder first.

 

[Mousetrap]

www.eccentricengineering.com.au Have a look on this web site as jack620 suggests.

 

[Mac McCaskie]

Thanks Jack620 & Mousetrap, I found what I hope is similar at https://www.carbideanddiamondtooling.com/
I sure wish the vendors used the same terminology. Reading the following requires a college education

1714-TBL632C P, T, Type Cut Off Blade,High Speed Steel, Cobalt, M4PM, T15PM, .040 to 5/16 Wide,3.5 to 6.5 Long ID 1714-
Select Tool Bit: P-2 3/32 1/2 TBL632C

 

[Shopgeezer]

I have the diamond tool holder from Eccentric engineering and I like it a lot. The parting tool gives me pause since you use it upside down and turn the chuck backwards. But, I like their products so might take a chance on their parting off tool setup.

 

[jack620]

To clarify, I don’t have EE’s inverted parting tool holder. I just have their 2mm cobalt blade mounted in an Aloris clone toolholder. The type that holds the blade at a slight angle. Because it’s a T blade you need to place a shim between the tool holder and the side of the blade to make it vertical.

 

[jack620]

Here it is.

 

[BaronJ]

I have the diamond tool holder from Eccentric engineering and I like it a lot. The parting tool gives me pause since you use it upside down and turn the chuck backwards. But, I like their products so might take a chance on their parting off tool setup.

No you don't !!!
You run the lathe in the normal anticlockwise direction !
But you do put the blade in the rear tool post upside down.

Putting the tool upside down in the front tool post and running the lathe backwards will cause problems because it will try to lift the front of the cross slide up. That is not good, and there is also the very slight risk of a jam loosening a screw on chuck.

If you don't have a rear tool post, just use the parting blade as you would use any other lathe tool.

 

[bruedney]

No you don't !!!
.

That is not right. According to EE's web site (https://www.eccentricengineering.com.au/index.php?option=com_content&view=article&id=36&Itemid=107) the holders can be used with the lathe running either forward or reverse. I have one and run it upside down in my normal toolpost with my lathe in reverse. No problem and much less butt clenching done

Bruce

 

[goldstar31]

John is like me by following a very long development on Parting Off which utilises an inverted rear parting tool which is fitted to a turret headed fixture and has the tool pointed down so that the Eclipse hss tool only needs touching up for wear at the front and doesn't lose height or whatever. The lathe is run forwards so that in this case, the threaded and registered chuck does not loosen and break the expensive blades.
These have a 140 degree kerf ground along the top to do the same as the vee on the Tee tool blade in the original article here.
Both principles narrow the swarf being turned off as a ribbon to avoid possible jamming with further potential damage - and that is about it but---------
Obviously cutting a 140 degree kerf necessitates a modified abrasive wheel and perhaps a tool and cutter grinder of sorts and a LOT of dust. I saw this coming and I substituted a worn cut off disk which creates a rounded convex top to the blades rather than the recommended vee.

And being a bit of a skinflint is one way of getting a job done by using a normally worn out thin abrasive disk.

It has been so much of a success, the castings kit was just for small lathes but now a larger set is sold for larger and - ? more rigid machines.

John, I hope that you correct me but I think that is a fairly accurate account of things.

Others may have different ideas

Norman

 

[BaronJ]

Hi Norman, Guys,

No correction needed at all Norman.

Running a lathe in reverse with an inverted tool in the front tool holder is not a good Idea, irrespective of what EE says. The tool placed inverted with the cutting edge at centre hight puts the tool body above the centre line reducing stability and causes lifting of the saddle.

 

[Shopgeezer]

I bought my EE stuff in the past from Bay-Com but apparently they no longer exist. Is there another N. America distributer anywhere?

Parting always seems to bring out a whole variety of opinions. BaronJ aren't the forces the same with a rear mounted tool holder using the parting tool upside down and running the chuck in the normal direction? You don't have to worry about the chuck unscrewing but the tool body is still above the centre line and is still lifting the saddle.

 

[jack620]

BaronJ aren't the forces the same with a rear mounted tool holder using the parting tool upside down and running the chuck in the normal direction? You don't have to worry about the chuck unscrewing but the tool body is still above the centre line and is still lifting the saddle.

That's what I'm thinking. I can't see the difference. If you watch the EE video he parts off an 8mm high-tensile bolt in a Sieg mini lathe without any issue. Having met Gary and visited his factory I'm very confident he wouldn't sell something that didn't work as advertised.

 

[coulsea]

I use the EE setup in reverse and it works, you do need to lock the carriage and the top slide and have the QC toolpost tight. I think that EE do say that you don't use it that way on a screw on chuck. A rear toolpost would defiantly be the best solution but we don't all have that facility on our lathes.