CATRA Lab Results: Knife Grinder Protocols Yield Superior Edge Retention

[BeSharp]

In 2025 I sent 25 knives (Mercer, Victorinox, and Global) to the Cutlery and Allied Trades Research Association ("CATRA") in Sheffield, England for Initial Cutting Performance ("ICP") and Cutting Edge Retention ("CER") testing under International Standards Organisation ("ISO") BS EN 8442-5, or, "Specification for sharpness and edge retention test of cutlery".

This was Knife Grinders of Australia ("KGA") Vadim Kraichuk's next project, according to his web site.

Sharpening and deburring were done either by me (BeSharp Sharpening) using KGA protocols (or variations thereof), or by four commercial sharpeners using their own protocols.

Higher CER values indicates longer edge retention. Using KGA's recommended protocols resulted in CER averaging 2.45 times longer than those four commercial sharpeners. It is also 2.66 times longer than the ISO 8442-5 mandated minimum CER. This is outstanding, considering three out of four knives sharpened and deburred by two of the four commercial sharpeners failed ISO 8442-5.

CER also depends on the steel used. Using KGA's recommended protocols, Mercer knives (X30Cr13 steel) lasted 19% less than Victorinox knives with X38CrMo14 steel. Global knives (CroMoVa18 steel) lasted 23% longer than Victorinox. Put another way, Globals lasted 46% longer than Mercers.

The KGA protocol was successfully varied in two ways to be faster and be cheaper. CER did not depend so much on the type of machine, but on the deburring method. One method that gave very good CER was with a Tormek T8, then deburring with the CW-220 Composite Honing Wheel with the guide bar height set for honing with the KS-123 Knife Angle Setter.

Download the 36-page report at my blog on my website: https://be-sharp.io/2026/01/09/catra-testing-cutting-edge-retention-bess-knife-grinders-australia/

Eric Ho
BeSharp Sharpening
Richmond, B.C., Canada
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[tgbto]

Thanks for sharing these results !

I read the report, which is very informative and detailed.

A few comments/questions, if I may :

First, there are many differences between the compared methods. The way I was taught, you have to make sure only one parameter varies when you want to make a comparison between two methods, and you have to have statistically significant samples. If I understood properly, you could very well have chosen the following titles for your report :
"Controlled Angle yields superior CER compared to Freehand" (which we have to say kinda makes sense) or if we wanna get cheeky :
"Round sharpening and honing medium yield superior CER compared to flat ones" or even :
"Eric Ho gets better CER than other sharpeners"  .
The huge difference in methods may only allow to increase confidence that "better sharpeners get better BESS *and* ICP", rather than infer a second-order polynomial relationship between BESS and ICP. There are mainly four clusters, you have a high chance of being able to fit those rather well with a second degree polynomial. It would also be true if you plotted BESS score vs age of sharpener.
[EDIT]Wootz and L. Thomas seem to agree on an empirical formula that ties edge retention to hardness/composition of the steel and edge angle only, which would imply ER only depends on BESS scores to the extent that higher wear-resistance steels allow for better initial sharpness. Also, a basic razor blade has very low BESS, but low wear resistance and poor edge retention.[/EDIT]

More seriously, if we look at the graph on page 20, but only take your results into account... Why can't we conclude "better BESS scores yield worse ICP overall" ?  That would be consistent with what several sharpeners have reported, when polishing the edge. I tried to guess the ICP/BESS values from your graph to put it inside an Excel spreadsheet and look at the global tendency, as shown on the attached image. That can only be proven true or false (or unrelated) by having a bigger sample and controlled variation of experimental parameters.
I understand it is a very complex thing to do, but changing so many things between two subsets makes it hard to draw any conclusion.

More on the "controlled angle" part. Wootz and Larrin Thomas concluded that angle was by far the most important factor in edge retention. So it would seem natural that methods that yield lower edge angle spread also yield better CER. That would also seem consistent with the fact that Wootz himself seemed to hint that others methods work well, without the whole paper wheel buffing shebang. But what about the Tormek protocol : grind using SG, hone using leather ? What BESS for what CER, when done by Eric Ho ?

A word on the Ken Onion WorkSharp : I own it as well as the T8, and am by no means a professional sharpener. I set it up with a FVB so I can better control the angle. While I consistently get 100-110 BESS @15dps using a simple protocol on the T8, I usually get 120-140 BESS with the WorkSharp with the fine belt followed by honing on a leather belt with Tormek compound. So a professional sharpener being satisfied with 250 BESS leaves me... flabbergasted. Side note : I only use it on lowest speed unless I need to grind a bolster.

Hope this helps with this edge retention topic, which I believe is indeed key to knives sharpening.

Nick.