Posts: 41
Threads: 4
Joined: Jun 2018
I wrote two very long articles on what factors control edge retention of knives. That includes the steel, hardness, and edge geometry. I had to analyze a huge database of CATRA tests from a major knife manufacturer. There were a lot of questions answered and it's too much to summarize here. I hope you like the two articles:
https://knifesteelnerds.com/2018/11/19/s...retention/
https://knifesteelnerds.com/2018/11/26/s...etention2/
Posts: 500
Threads: 38
Joined: Mar 2017
Thanks for the links Larrin and we're going to have a read at our first opportunity.
Posts: 41
Threads: 4
Joined: Jun 2018
11-29-2018, 11:28 AM
(This post was last modified: 11-29-2018, 02:01 PM by Larrin.)
(11-27-2018, 09:48 AM)EOU Wrote: Thanks for the links Larrin and we're going to have a read at our first opportunity.
That’s code for “these articles are too long.”
Posts: 500
Threads: 38
Joined: Mar 2017
And big words too!

Do you find it intuitive that lower sharpening angles indicate less wear than higher sharpening angles? Perhaps that question is not stated correctly and there might be a difference so here is the the same question stated differently. Do you find it intuitive that lower sharpening angles cut more card stock than higher?
Secondly, saw a reference to PSI once but it wasn't clear if that applied to the amount of force exerted on the blade or not. Do you know how much force was applied to the blades during the tests?
I'll say the same thing here as was posted in the comments section of your blog. Thank you for the work expended by both you and your contributors in putting the articles together and thank you for making the articles available to us all.
Posts: 41
Threads: 4
Joined: Jun 2018
11-30-2018, 02:11 PM
(This post was last modified: 11-30-2018, 02:11 PM by Larrin.)
Thanks!
Yes the more acute angle edges have much higher cutting ability so they have to wear a lot more to reach a lower level of cutting ability. That all seems intuitive to me.
The only reference to psi was in relation to Crucible crossed-cylinder wear tests. The load on the knife in the CATRA test is 50N.
Posts: 500
Threads: 38
Joined: Mar 2017
Thanks for the quick answer Larrin. If we remember correctly our friend Grepper did some tests push cutting a raw baking potato with a 150 edge and came up with a 4-6 pounds of force requirement. 50 Newtons is about 11 lbs. of force if that serves to provide anyone with a better frame of reference for the experiment.
Posts: 12
Threads: 0
Joined: Jan 2019
Mind blowing articles. Thanks for sharing Larrin!