There is a discussion on somewhat here and on the "Edge Matters" forum, A British forum that I've had a good time being part of. (which would enjoy your presence). They're a bit "daft", but they have a great sense of humour and are quite knowledgeable about knives.
Many have noticed that some knives will get duller with no use. Why?
For someone who has proper testing equipment, this would be an interesting avenue of experimentation. Sharpen knife, test it. Wait a week, test it. Wait another week, test it again.
Many have noticed that some knives will get duller with no use. Why?
sal
I am one of the folks here with comparably very little knowledge about steels and sharpening, but I think this "getting duller with no use" has to be due to edge degradation by (however slow) corrosion at the very apex?
Total layman here, though. Quite the complete opposite of Dr. Larrin , I hope he´ll chime in!
Top three going by pocket-time (update March 24):
- EDC: Endura thin red line ffg combo edge (VG10); Wayne Goddard PE (4V), Endela SE (VG10)
-Mountains/outdoors: Pac.Salt 1 SE (H1), Salt 2 SE (LC200N), and also Wayne Goddard PE (4V)
I've noticed this as well. Seems to vary from knife to knife and steel to steel. I've always blamed it on the knife gods just messing with me. However it has been a contributing factor in my habitual need to have a good pocket stone handy at all times.
Maybe stress-induced carbide precipitation due to sharpening? Sharpening a blade will cause tension in the edge resulting in carbides trying to reach a state of relaxation? You see this same effect in bearings.
Maybe stress-induced carbide precipitation due to sharpening? Sharpening a blade will cause tension in the edge resulting in carbides trying to reach a state of relaxation? You see this same effect in bearings.
Interesting! Would have never thought of that, since I have no idea of such things
Top three going by pocket-time (update March 24):
- EDC: Endura thin red line ffg combo edge (VG10); Wayne Goddard PE (4V), Endela SE (VG10)
-Mountains/outdoors: Pac.Salt 1 SE (H1), Salt 2 SE (LC200N), and also Wayne Goddard PE (4V)
When I took chemistry a million years ago (it seems) I think I remember my prof saying that a knife edge will loose atoms and so will a diamond, over time. How long that takes, I don't know.
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Back in the late '70s, I read an article in a knife publication at a book store. I specifically remembered the article mentioning oxidation as the cause of knife edges becoming dull over time from just sitting around, especially on straight carbon steel blades.
I might have dreamed this, as I can't find the link now. But I have a fuzzy memory of reading a thread on blade forum years ago talking about this phenomenon. I think it was specifically regarding 440C. Rust was considered less likely since 440c is pretty stainless (and regarding other oxidation, I'm pretty sure whatever chromium oxide layer that forms on fresh steel is near instantaneous).
There was no conclusive answer. But someone mentioned some alloys returning to shape after deformation. Reading about shape memory alloys, they seem to not relate to steels used in knives. But perhaps knife steel exhibits this property in a very small capacity? That is a big if, predicated on the even bigger if, of whether sharpening counts as deformation.
That subject has come up several times over the last couple decades but no one has pinned it down. Corrosion, steel "relaxing", and burrs are brought up amongst other theories . Some argue it doesn't happen at all.
The edge testers are available now and we are closer to finding out if it really exists. After that then on to the why. Aside from the obvious ones anyways.
That subject has come up several times over the last couple decades but no one has pinned it down. Corrosion, steel "relaxing", and burrs are brought up amongst other theories . Some argue it doesn't happen at all.
The edge testers are available now and we are closer to finding out if it really exists. After that then on to the why. Aside from the obvious ones anyways.
It is funny, because without equipment, it is hard to pin down "This knife is not a sharp as it was when i sharpened it 3 months ago." It does keep coming up so maybe there is something to it. I know I have had that feeling with S30V, especially when I carry it but don't use it for a period. Did the edge just rub something in my pocket, did I cut a few things with it I forgot about, did I just remember it being sharper than it was or can some steels dull with little or no use over time.
I have brought this up several times. The high carbon tool steals will feel less sharp after a week where I live with no use. I now put Chapstick on the edges and sometimes the whole blade and put them in Ziploc bags.
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, I hope he´ll chime in!
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Mule Team Army 001
Stable Mules; Z-Max, Z-Wear, Magna Cut, SRS13, Rex 76, Rex T15.
