Knife Edge Toughness Tests

[Larrin]

I wrote an article about the published quantitative tests for knife edge deformation and chipping. There are plenty of people out there chopping into wood, bricks, etc but what is out there in terms of a repeatable test? Can charpy impact and other toughness tests be related to edges of knives? Is there any point in doing toughness testing for knives that are designed only for cutting and not hard use?

https://knifesteelnerds.com/2018/08/13/tests-of-knife-edge-toughness/

 

[A.McPherson]

Interesting article Larrin, thanks for posting!

 

[Justin Schmidt]

Larrin is there a test or research done to fund our what steel has the ability to get the sharpest? What alloying elements allow a knife to get sharper? I'm always interested in how sharp a knife can get

 

[DevinT]

Larrin is there a test or research done to fund our what steel has the ability to get the sharpest? What alloying elements allow a knife to get sharper? I'm always interested in how sharp a knife can get

Small carbides and high hardness.

Hoss

 

[Drew Riley]

Larrin,
This might be somewhat tangential to the original post, but
have you seen the “PT50” series of sharpness testers? They use a filament over a scale to measure cutting force of an edge. I’ve seen other similar jigs that are a bit more elaborate, but just curious what you think of them as a standard of measurement for things like edge sharpness, retention, etc... Seems like an interesting alternative to CATRA tests, though I wonder how consistent/repeatable it can be.

 

[Larrin]

Larrin,
This might be somewhat tangential to the original post, but
have you seen the “PT50” series of sharpness testers? They use a filament over a scale to measure cutting force of an edge. I’ve seen other similar jigs that are a bit more elaborate, but just curious what you think of them as a standard of measurement for things like edge sharpness, retention, etc... Seems like an interesting alternative to CATRA tests, though I wonder how consistent/repeatable it can be.

I briefly talked about that sharpness tester in this article: https://knifesteelnerds.com/2018/08/06/sharpness-vs-cutting-ability/

I don’t think there is anything inherently wrong with it. I’m probably going to buy one.

 

[Stromberg Knives]

Larrin,
This might be somewhat tangential to the original post, but
have you seen the “PT50” series of sharpness testers? They use a filament over a scale to measure cutting force of an edge. I’ve seen other similar jigs that are a bit more elaborate, but just curious what you think of them as a standard of measurement for things like edge sharpness, retention, etc... Seems like an interesting alternative to CATRA tests, though I wonder how consistent/repeatable it can be.

I'm very happy with mine, as long as you understand its pros and cons. And what you actually are measuring.

I bought mine to get a consistent sharpening output. I want my knives specs to be as quantifiable as possible. I.e I measure hardness with a hardness tester and I measure my edges with a sharpness tester.