Sharpening High Vanadium Knives

[wootz]

Please see our last research comparing sharpening high vanadium knives using aluminium oxide versus CBN/diamond abrasives.
This comparison has been done on knives with vanadium content of 1%, 2%, 3%, 4% and 10%.

Link to the report on the BESS forum: Edge Rolling in High Vanadium Knives >
more: Edge retention by hardness, carbon content and wear-resistant alloys >
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This must be especially interesting for fellow tormekers, as all sharpening was done solely on Tormek machines.

Excerpt:
"Numbers tell us that edge rolling does depend on whether we sharpen with aluminium oxide or CBN/diamond, and CBN/diamond gives better lasting sharpness than aluminium oxide, but correlation with the vanadium content it is not linear – instead, there is a
dramatic rolling in edges with vanadium content of 3% sharpened with aluminium oxide."

"The high-vanadium edge sharpness quickly moves beyond the shaving range to just sharp. In the first impacts a 10% vanadium edge apex rolls to the same extent as a 3%, and both the 3% and 10% vanadium edges lose their initial keenness almost at the same rate as a mainstream knife.
Higher wear-resistant blades win as stayers, but are equal sprinters.
As one of our readers has commented: "Which may explain why s110v loses it's keenness rather quickly but is able to keep a working edge for a long time"

[kwakster]

Interesting reading material Vadim, thank you.
Have you thought about incorporating silicon carbide in the test as well ?

[RickKrung]

Wootz,

Excellent work.  I hope this clues some Tormekers to look harder at all the great work happening on the BESS exchange.  I have certainly learned a huge amount from it. 

Thanks. 

I think you should post a link/discussion on your testing of bevel angle and edge retention.  It is not at all Tormek centered, but as such, I think it has more universal application, for all sharpeners and Tormekers should be paying attention. 

I am delighted, however, to read about the differences of the grinding/honing mediums used on the Tormek.  I think it would be very informative if this sort of information were available for the more common steels found in pockets and kitchens.  I think if it holds true for the non-vanadium alloys, it will fuel a larger shift towards the yet to be released suite of diamond Tormek wheels.  I was already leaning heavily but have not yet placed an order.  This may have put me over. 

Thank you for all the great work you are doing to further knife edge sharpening and testing.  I always enjoy reading your posts, always informative and well written. 

Rick

[wootz]

Thank you Rick and kwakster
Research just have to be thorough as what I find out we apply to our business.
I've done this research because we sharpen high-end knives, and did the previous research with meat plants in mind  Edge Stability in Butcher's and Kitchen Knives as a Function of Edge Angle and Initial Sharpness

kwakster, I wish I had time to check silicon carbide abrasives, but we don't use them much in our workshop and not a priority for us unfortunately - where we used to sharpen on the SB, we sharpen on CBN wheels these days.

BTW, SHARPCO - you asked how sharp can Tormek sharpen knives - we were getting 80 BESS with no effort on Tormek stock wheels with Tormek honing paste during this research, and on a few occasions the knives scored 60 Bess.

[Fedor]

Thank you, Vadim.
The stuff is very good. But as always. I learned a lot of useful things for myself.

[wootz]

My pleasure, Fedor.
We ourselves learn a great deal with each research that makes us scratch the head. Reality is often more weird than our imagination, we've learnt we should not assume as we start a research, because the assumptions turn wrong as we finish.
For example we wouldn't imagine this before we got the experimental data: http://www.bessex.com/forum/showthread.php?tid=326