What's the best parting tool?

cascao said:
In an hobby lathe I think that the thinnest is best.
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(later note: I'm not wanting this to be aimed at cascao as I degress from the topic)

That is a very good thought but sometimes not exactly best. The thin blades work very well indeed in the hobby lathes that the chuck bolts on or is keyed so you can flip the tool upside down and turn the lathe backwards so gravity clears the swarf and coolant. Going a bit thicker is better for a lathe with a threaded spindle since that geometry (upside down and backwards) could loosen the chuck unless it locks.

Parting is all about the swarf. If the swarf isn't clearing then the parting will be more exciting than is optimal before the pieces separate. We don't need that. If you are running a part and the swarf changes be ready to stop.

The wonderful thing about hobby machining is we work with what we have and still get great results, no matter. I modded an old lantern post CO holder by welding a piece of 1/2" HS to it and used it to good results for a while. I still use it to part AL faster than the horizontal bandsaw can cut it.

Steve
 
swatson144 said:
I bought an Iscar knockoff from shars. For around 80$ last year for the wife to give me for Christmas :) http://www.shars.com/product_categories/view/80306/Positive_Stop_Blade__Tool_Block_Sets
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We use Kennametal Iscar knockoffs at work but I wasn't feeling that spendy. The shars has seen a good deal of use and I am very pleased with it. It cuts square and deep even with the inserts included in the kit. Usually I find that replacing import inserts is well worth it.
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The spruel folds into the middle and rolls out like a coin for chip control just like it should. I just feed in at .007"/r and watch it happen. YMMV

Steve
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I ended up getting the 3/4" version of this:http://www.shars.com/products/view/18869/34quot_Positive_Stop_Blade_Cutoff_Set which comes with two blades and inserts for both and also a 3/4" XL BXA tool holder. That's as beefy as my lathe will take. :)) I've had really good experience with shars stuff in the past.and that one seems like a really good value.

The idea of inching the parting tool out of the holder incrementally is a good one. I should have thought of it. And I will do it even with the new parting setup, But this was the straw that broke the camels back, I've been wanting a better, more rigid, parting tool for a long time now. After a while, I just get tired of playing around and making due with crap!:whiteflag:
 
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Plus whatever on the Iscar system. I got one as part of another purchase. I use it now exclusively. Way better than those old fashion exploding parting bars.

Randy
 
If it's a deep cut, start the groove with a cutoff tool and then remove the part from the lathe and bandsaw it apart. You could also hacksaw it off directly on the lathe (with the lathe turned off). Before I get flamed, sometimes you have just have to be reasonable and expedient. The cut edge can easily be faced off and/or faced to dimension.
 
KenS said:
If it's a deep cut, start the groove with a cutoff tool and then remove the part from the lathe and bandsaw it apart. You could also hacksaw it off directly on the lathe (with the lathe turned off). Before I get flamed, sometimes you have just have to be reasonable and expedient. The cut edge can easily be faced off and/or faced to dimension.
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That's exactly what I did this last time after the cut-off blade went flying. Then I had to re-indicate it in the 4-jaw to finish off that side of the piece. No big deal I guess. It could have been worse ....I could have had the cut-off blade for dinner, thankfully it went flying towards the back wall, away from me. :phew:
 
Nice find but the drawback to that one is it doesn't have the "positive stop" nub behind the insert so as you are parting the insert can be forced deeper into the holder and lower the cutting edge and require more force and begins a sequence of sub-optimal events. Some who know me may claim that sequence begins whenever I get in front of a machine.

That exact design was used for years to good effect and then came the "Positive Stop" upgrade. I certainly wouldn't be concerned with the GTx-6 holders but the smaller GTx-3 and especially the GTx-2 holders.

Steve
 
ridgeway said:
$54 at Grizzly...

http://www.grizzly.com/products/Parting-Tool-with-Carbide-Insert/T10012

t10012.jpg
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We had a similar looking INSERT in MITSUBISHI CARBIDE and crashed a good couple of times !!!
Then we read a thread on HMEM and got ourselves the ISCAR's. These solved our "flinch-fears".
And even better was getting to read TOM LIPTON's book "METALWORKING - SINK OR SWIM" where he recommended POWER FEEDING - obviously at the right SPEEDS !!!
Works like a charm.
He has some ingenious, practical and work-tested ideas which we would highly recommend to all Hobbyyists and even pros alike.
Do Yourself a favour and get a copy, today.
All the best
aRM

t10012.jpg
 
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swatson144 said:
I bought an Iscar knockoff from shars. For around 80$ last year for the wife to give me for Christmas :) http://www.shars.com/product_categories/view/80306/Positive_Stop_Blade__Tool_Block_Sets
View attachment 67293

We use Kennametal Iscar knockoffs at work but I wasn't feeling that spendy. The shars has seen a good deal of use and I am very pleased with it. It cuts square and deep even with the inserts included in the kit. Usually I find that replacing import inserts is well worth it.
View attachment 67294
The spruel folds into the middle and rolls out like a coin for chip control just like it should. I just feed in at .007"/r and watch it happen. YMMV

Steve

View attachment 67293 View attachment 67294
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Old thread, but it came up on suggested threads up top and I'm looking at these so thought I'd ask.

For those using the shars like above, is the .120 size inserts a good size for a 1340 lathe? Should I get smaller/bigger?

Shars insert number is GTN-3, is there a quality insert that interchanges or are these decent enough?
 
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