- Joined
- Dec 28, 2010
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- 30
I saw a pretty interesting thread in a shooting forum about knives.
Apparently, knives will lose sharpness over time, even when not used at all, and not exposed to rust or corrosion.
I've posted links to the entire discussion below, but here are some of the highlights:
"It doesn't really matter what method you use for sharpening, after 24hrs of the knife sitting idle it is half as sharp, that is, it loses a large portion of its sharpness by just sitting around for a short time. For a while they put this down to oxidisation of the cutting edge however recent experiments have eliminated that. Their best determination is that sharpening of any type creates stresses and distortions in the fine cutting edge that afterward relax which removes some of the gains. This happens fairly quickly, in a matter of hours. Sounds like a real bummer however there's a simple solution, that is before you use your knife simply give it a quick and light strop on leather. They've even tested how much stropping is best and concluded two strokes at 12 degrees each side are better than many strokes. Using a steel also works as long as it's not one with large and aggressive serrations. Apparently this light action resets the cutting edge to straight. (They have many micro-photos to prove it).
So, the take home is, sharp or not, strop or steel your knife briefly and lightly before every use if you want the best from it."
"The effect appears to be slightly less in high end steels. It's also slightly less if you use certain types of sharpening devices, especially those that rely on swinging diamond plates, such as TSProf or Edgepro, where you can control the application of force.
However remember that half as sharp is a relative term. Sharpness in these cases was measured in BESS units, which is a machine that measures the force taken to cut a known nylon wire, so essentially given in grams. So, what do I mean by relative? Well, if for example a knife cuts at 50 BESS it is sharper than a commercial razor blade. After 24hrs it is cutting at 100 BESS, which is still sharper than most chefs knives. So, it's not that your knife becomes a hammer overnight. The point is as Wayne says, you may have noticed this effect and now you know it's real. So a quick strop or steel before each use and all's good.
At last years Adelaide Knife Show there was a prize for the sharpest knife. It was won with a kitchen blade then went 35 BESS, which is so sharp it's unbelievable. The same knife was tested at the recent Sydney Knife Show, a year later and though unused in any way it measured 50 BESS, which is still twice as sharp as the best chefs knives, but half as sharp, if you see what I mean. A quick strop on untreated leather and it was back in the 30's. It's good that there is such a simple solution to this."
https://www.ballisticstudies.com/Resources/Discussion+Forums/x_forum/22/thread/17793.html
https://www.ballisticstudies.com/Resources/Discussion+Forums/x_forum/22/thread/17109.html
Apparently, knives will lose sharpness over time, even when not used at all, and not exposed to rust or corrosion.
I've posted links to the entire discussion below, but here are some of the highlights:
"It doesn't really matter what method you use for sharpening, after 24hrs of the knife sitting idle it is half as sharp, that is, it loses a large portion of its sharpness by just sitting around for a short time. For a while they put this down to oxidisation of the cutting edge however recent experiments have eliminated that. Their best determination is that sharpening of any type creates stresses and distortions in the fine cutting edge that afterward relax which removes some of the gains. This happens fairly quickly, in a matter of hours. Sounds like a real bummer however there's a simple solution, that is before you use your knife simply give it a quick and light strop on leather. They've even tested how much stropping is best and concluded two strokes at 12 degrees each side are better than many strokes. Using a steel also works as long as it's not one with large and aggressive serrations. Apparently this light action resets the cutting edge to straight. (They have many micro-photos to prove it).
So, the take home is, sharp or not, strop or steel your knife briefly and lightly before every use if you want the best from it."
"The effect appears to be slightly less in high end steels. It's also slightly less if you use certain types of sharpening devices, especially those that rely on swinging diamond plates, such as TSProf or Edgepro, where you can control the application of force.
However remember that half as sharp is a relative term. Sharpness in these cases was measured in BESS units, which is a machine that measures the force taken to cut a known nylon wire, so essentially given in grams. So, what do I mean by relative? Well, if for example a knife cuts at 50 BESS it is sharper than a commercial razor blade. After 24hrs it is cutting at 100 BESS, which is still sharper than most chefs knives. So, it's not that your knife becomes a hammer overnight. The point is as Wayne says, you may have noticed this effect and now you know it's real. So a quick strop or steel before each use and all's good.
At last years Adelaide Knife Show there was a prize for the sharpest knife. It was won with a kitchen blade then went 35 BESS, which is so sharp it's unbelievable. The same knife was tested at the recent Sydney Knife Show, a year later and though unused in any way it measured 50 BESS, which is still twice as sharp as the best chefs knives, but half as sharp, if you see what I mean. A quick strop on untreated leather and it was back in the 30's. It's good that there is such a simple solution to this."
https://www.ballisticstudies.com/Resources/Discussion+Forums/x_forum/22/thread/17793.html
https://www.ballisticstudies.com/Resources/Discussion+Forums/x_forum/22/thread/17109.html
