hollow-ground parting tool

Max,

The hollow grind on a parting tool (aka narrow skew) isn't too much of a problem unless the tip of the tool is just so long and thin as to be unstable and/or flimsy enough to possibly break. Personally, I don't like hollow grinds of any kind on any of my tools but that's more a function of how I work with them and the uses I put them to.

- Andrew

Neat idea for sharpening the tool! I think I'll try it...

Peter Teubel Milford, MA

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The parting tool to which I was referring isn't a diamond section tool, rather an inexpensive rectangle-section one from Harbor Freight. However my Sorby IS a diamond parting tool, and I was wondering if it was possible to grind it on it's side. Thanks for the website. Bookmarked, as usual.

I don't like hollow grinds either, which is why I adopted your system of a disc mounted to a lathe spindle. It works nicely for removing the hollowing from my gouges, etc. But the parting tool, with its long facets, presented a problem. I wore out two aluminum oxide discs attempting to get the facets flat. I'll try the side-grinding method.

Max

I came up with the grove in the toolrest (or a grooved block on top of the toolrest if you don't want to mess with your toolrest) for the diamond parting tools when I was giving a sharpening workshop a few months ago. I was showing the method of sharpening the parting tools on their sides when a fellow asked what to do with the diamond shaped one because it kept tipping on him. The groove works pretty well but it's not the perfect solution. The perfect solution is to clamp it down in some jig and slide that whole assembly up to the wheel/disk. But who has the time or patience to do that everytime?

One of the things I like about the sanding disks is that you can position the tool being worked on so that you can sight straight down on the bevel and see what you're doing.

- Andrew

If you don't like the hollow grind, you could try putting a convex grind on it as they do on the Eli Avisera tools made by Hamlet Craft Tools. It works well and despite being the opposite to everything we've been taught, they do work and work well. I also use this grind on the skew chisels and rarely pick another up.

Hamlet Tools are at

and Eli has hisown site at He is a brilliant turnerand if you get a chance to see him, his turnings will have youcaptivated. Regards

Paul

The hollow grind on your parting tool will only be a problem if you are parting anything with a larger diameter than your grinding wheel. Think about this one !

The main thing is to get the right bevel angle at the tip (after all, that's the end that matters).

Another way around a long hollow ground bevel is to grind a double bevel, one at the tip with the right angle and one some way back at a shallower angle.

Hope these suggestions are of some use.

Cheers

Paul

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Amen to that. Due to the very small cutting edge of a parting tool, it seems to dull rather quickly, especially when turning woods such as teak. Frequent sharpening appears to be necessary.

That's pretty well been my experience. While I'd love to have a nice jig system for all my tools, it simply isn't practical, especially if one's time for turning is as limited as mine. I'm beginning to gain a modicum of proficiency with eyeballing my freehand sharpening, and I attribute much of that to the ease of use of the sanding disc system.

Max

I understand this. So far nothing approaching that diameter has been an issue.

I wondered if this might be acceptable. I think I like the concept of grinding the parting tool on its side better.

Thanks for the suggestions, Paul.

Max