What size (thickness) HSS Cobalt Parting Blades?

[GrahamC]

Subject line says it all.

This is for use on my 10x22 size Asian lathe with an AXA size QCTP. Mostly turn steel (1018, 1144, 12L14, 4140 - in other words CRS, leaded free turning steel, and Chromoly), some brass, and occasionally 7075/2024 and 6061 aluminum in that order.

I currently am using an Asian import 3/32 wide by 1/2 HSS maybe M2 of some questionable quality; it was inexpensive. I can sharpen it without any issue and it does reasonably good work. It is not a "P" type (ie T cross section) but rather has a double taper.

Now, I am not one to have much if any issue with parting but since I tried working some titanium a couple of weeks ago this parting blade just hasn't been the same despite repeated re-sharpening.

So, I am thinking it is time to replace the blade with something of better quality. Easy enough done but I am fussing over the blade width for reason.  I am considering a "P" type (T cross section) of 1/16", 5/64", or 3/32" width.

I have been using a 3/32" wide blade for a long time with few issues and I don't have the wisdom of failure in this area to help guide me to make a choice.

Some research gives the recommendation of using a thinner blade (i.e. 1/16") but why mess around with success?

So, what say ye learned souls, what size (thickness) - go for the thinner (and why), stay with the current size, or split it down the middle 'tween the two (and why)?

And before you recommend an insert cut-off / parting tool, I have been considering that too.


cheers, Graham in Ottawa Canada

[ksouers]

Graham,
I use a 1/16 parting blade and it works fine on small diameters. But on larger stuff, say 1 inch or bigger, it tends to want to wander sideways. I'm thinking of getting a thicker blade to compliment my thinner one for the larger diameters.

I guess it depends on what size material you want to part. The thicker one will definitely be stiffer.

[bogstandard]

Graham,

I think you have found the perpetual problem.

I must have at least half a dozen different parting tools, from very simple to the rather unique, and another one on the way to me.

All have their own little foibles, but they do allow me to cut almost anything with relative ease.

I don't think you will ever find one that is a cure all, but if you are lucky you might find one that 'copes' with a range of materials.

You are just one of very many wandering in the wilderness, trying to find the ideal solution, when there isn't one.


Good luck on your quest.


John

[GrahamC]

Graham,

You are just one of very many wandering in the wilderness, trying to find the ideal solution, when there isn't one.

Good luck on your quest.

John

Thanks guys,

There may not be an "ideal solution" but it is often possible to get close.

After some more sittin' and thinkin' (and a bit of stinkin') on the throne again (sorry, wasn't the curry this time), plus mix in a bit of online research - I think I have reached a good set of compromises that should see a solution that while not ideal in all cases, should suit my needs quite handily. I will post details as they develop but in the meantime I will just keep it to myself.

Yes indeed, I am but one of the many wandering the wilderness; after all, the journey is the purpose I wander and ponder the un-ponderable - not the answer.

cheers, Graham  off to wander and ponder some more and take the dog for a walkies.