Steels that retain toothy edge and have a bite even when polished to higher degree???

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lonestar1979

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My favourite steel 12c27mod that they use in Opinels retains toothy edge and has abreally nice bite even when polished to higher degree.This is not the case with some other steels where they just slide off soft materials that youre cutting.Which other steels retain toothy edge even when polished?Opinels with carbon steel I have to leave sil carbide medium finish or dmt medium to have the same bite.
 
I can't really answer your question about other steels with the properties you are asking about. However, I can say that my carbon steel Opinels do really well off Arkansas stones. I usually progress from soft to hard to hard black stones, but I also have taken to hitting them with a DMT fine diamond hone first if I have really dulled them. The Arkies are not terribly aggressive and I think they polish the edge well while leaving the deeper scratches from the diamond in place to form a toothy edge that appears to be polished (though it isn't like a mirror edge).
With that in mind, perhaps this isn't really a question of steels and more about sharpening methods. In my opinion, a truly polished edge has those deeper marks on the bevel from coarser stones smoothed away. My thought is that a polished edge will loose the micro-serrations. Polishing to a lesser degree or possibly changing the angle of the finer stones in relation to the blade such that they do not actually hit the very edge may help.
 
lonestar1979 said:
My favourite steel 12c27mod that they use in Opinels retains toothy edge and has abreally nice bite even when polished to higher degree.This is not the case with some other steels where they just slide off soft materials that youre cutting.Which other steels retain toothy edge even when polished?Opinels with carbon steel I have to leave sil carbide medium finish or dmt medium to have the same bite.
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That's exactly what I've noticed about my Opinels, regarding behavior of the 12C27Mod vs. their XC90 'Carbone'. Saw the thread title and they immediately came to mind. I honestly don't know if I've seen any other stainless exhibit that same 'micro-tooth' (how I think of it) when more polished. It's not something I feel with the fingertips, but more in the way it still 'zips' through paper when test-cutting for sharpness.

Most of what I noticed with the 12C27Mod came during a period when I was sharpening edge-trailing on wet/dry sandpaper up through 1000-grit or so, and then stropping on wood-backed denim with some white rouge compound (aluminum oxide rated at 2-5 microns, as labelled). If methods had something to do with it, that's what I was doing with these at the time. Trying a similar approach with the XC90 always tended to polish the bite out of the edge very quickly.

Sandvik has a reputation for very high purity and very fine grain in their manufacturing process for their steels. I've sort of assumed, but I honestly don't know, maybe the behavior of their stainless has something to do with that at least. Maybe something in the little bit of chromium carbide content, if the carbides are very fine and respond well to certain polishing approaches, effectively making very durable little 'micro-teeth' along the edge. But that's just me speculating...
 
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Well, I hadn't considered that aspect of the steel. I am no steel geek, but it sounds reasonable to me.
 
The helle knife with laminated stainless behave almost same,its sandvik ss laminated,has excellent bite even when polished,other steels i have lose the bite if polished
 
Maybe the sandvik has a higher Rockwell??, what it sounds like to me
 
To my knowledge, Opinel has never published what they harden their stainless blades to. But Sandvik's specs for 12C27M say it's hardenable up to HRC 59. Whether Opinel takes it that far, I don't know. I'm pretty sure their 'Carbone' blades aren't close to that; they seem pretty soft. But, the stainless' edge retention is pretty good and less prone to rolling or deformation than their XC90 'Carbone' blades, from what I've seen in mine.

But even comparing to other stainless steels at similar or higher hardness, I still see something unique in Opinel's stainless, in how it retains that bite at higher finish. I haven't seen such character in other stainless steels; especially others in the same modest carbon content range (12C27M = 0.52% carbon; compare to something like 420HC or 440A in roughly the same carbon range). I still think it may have something to do with very fine and/or very evenly-distributed carbides, which would make the most sense to me. At that relatively low carbon level, there can't be that many (chromium) carbides in the steel to start with; but I can't help but think Sandvik is making the most of what's there (and Opinel doing the same, in their heat treat of the steel).
 
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Opinel inox performs better than their carbon ,doesnt lose that bite as fast and doesnt roll,i have few opinels in carbon,they tend to roll,but are very easy to sharpen.Inox that they use is also easy to sharpen ,maybe little harder than their carbon,but in my opinion cuts better and longer.It is literally straight razor sharp easily,i could shave with it if put it on high grit stone for sure.
 
lonestar1979 said:
They should heat treat carbon opinels 2-3 rc higher,i bet that would be awesome.
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I've wished for that, for a long time. :(

There's a trade-off between corrosion resistance and hardness (harder blades are more prone to rust, all other things being equal). Opinel might be playing it conservatively, in trying to minimize rusting issues in a folding knife with a wooden handle & pivot, known in their history to have issues with holding moisture. That's me speculating again, but that's the only logical reason I can see as for why(?) they haven't taken them harder.
 
lonestar1979 said:
some other steels where they just slide off soft materials that youre cutting.Which other steels retain toothy edge even when polished?
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Well after I read your title and before I read your question I was going to say S110V because the polished edge "crumbles" for lack of a better term and gets all micro toothy in a few days of cutting abrasive stuff. So yeah . . . that stuff.

Once I read your question it sounds to me like you are experiencing differences in edge geometry more than differences in steel characteristics.

An example is my over posted Little Monster at this LinkL>>>>
page down to the grape demonstration of edge bite.

THAT sir is a polished edge sharpened to around Shapton Pro 8,000 . . . a year and a half ago . . . come to think of it it is months older than that now. Still cuts great ! ! !
Read the text; I think it will surprise you. That knife never fails to please me.

If you want bite like you are describing and do not want the knife to slide on things like tomatoes and soft bread the first things I would do is sharpen what ever knife is failing to do this by putting on a shallower angle, thin the knife behind the edge (some times as much as half the thickness or more for example taking a knife that is 30 thousandths behind the edge down to 10 or 15 thou behind the edge) . . . and also while you are at it loose any strops you have been using and just put the final edge on with a stone . . . in my view a fine stone on the order of Shapton Glass 4,0000 or Shapton Pro 8,000 (what ever is most appropriate for the steel alloy).

NO MATTER WHAT STEEL (except that funny S110V that needs diamonds) you will be pleased . . . I guuuuurrranteeeee it.

Want to just relax and get 'er done quick ?
Use an Edge Pro; this will improve the geometry right on the edge even more :thumbsup: :thumbsup: :thumbsup:
 
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The edge that was sliding was stropped on green compound too much,i do not use strop anymore except bare leather.Still,some steels have more bite,some less,i thin out my knives a lot,then put invisible micro bevel on them at higher angle,when micro bevel gets visible i thin it out again ...but still edge finished on norton medium sil carbide stone or dmt cant be beaten for bite into soft materials.Have tried some water stones but still get better results with dmt or norton stone.
 
i am pleased with results i get,and get hair whittling edge on most knives,some steels just get sharper easier and have more bite at same finish than others.Maybe its matter of not just the steel but heat treat too.
 
Most of my knives that when stropped with diamond after sharpening to a mirror will have a toothy edge at the tip.
 
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Hi,
Why attribute a serration pattern to a steel type?
Why attribute a serration pattern to a steel Rockwell hardness?

Not that steel types (carbide volume) and hardness dont play some part,
but it mostly comes down to how its how its shaped and sharpened

geometry = angle + thickness
grits / strokes / pressure

freshly sharpened edge
on easy to grind steel
+ squishy pasted leather strop
+ lots of passes freehand
and slides off soft material
= rounded over apex (less sharp)

v.
freshly sharpened edge
on harder to grind steel
+ squishy pasted leather strop
+ same amount of passes freehand
and doesnt slide off soft material
= not rounded over apex on a strop (more sharp )
 
I sharpened few of my knives on japanese king waterstones,couple days ago,1-4k grit,and although theyre hair whittling sharp,cut well,still prefer norton sil carbide or dmt for that extra bite.
 
Why polish an edge?

I'd think polishing an edge files down the exposed carbides and kills abrasiveness for cutting capability.To me a polished edge feels like a decline in performance with any grade of steel.Seems like the only thing unaffected is the apex and the hell with the bevel.
 
Frotier76 said:
Why polish an edge?

I'd think polishing an edge files down the exposed carbides and kills abrasiveness for cutting capability.To me a polished edge feels like a decline in performance with any grade of steel.Seems like the only thing unaffected is the apex and the hell with the bevel.
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Some tasks require a mirror polish. It depends what your cutting. Just an example.... A sushi chief will use a mirror edge for cutting up fish. While a coarse edge is useful for cutting rope or cardboard (at least on some steels).

Some steel types may have a higher or lower edge retention depending on the finish also. It may also depend on the material or objects being cut as well.
 
Frotier76 said:
Why polish an edge?
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Hi,
To shave face
To shave wood
To chop wood
To chop foods
To maximize high sharpness edge retention when chopping or push cutting (slow chopping, no slice, no sawing)


Frotier76 said:
I'd think polishing an edge files down the exposed carbides and kills abrasiveness for cutting capability.To me a polished edge feels like a decline in performance with any grade of steel.Seems like the only thing unaffected is the apex and the hell with the bevel.
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Not sure what you're talking about.

Think of coarse apex finish as a saw,
sawteeth, they go up and down and up and down,

Saw teeth are great for sawing ( slicing ),
not great for chopping cause the teeth will dull quickly or break off.

When the entire edge is polished, its like one giant tooth, like an axe, no saw gaps
 
If the 'polishing' of the edge is done with the right abrasives (harder than the carbides) and substrates (firm/hard), the carbides won't just be filed down and rendered useless. They'll be thinned and shaped to good cutting geometry, just like the rest of the edge, and will still retain all of their wear resistance and durability in doing so. The thinned geometry (in cross-section) is what will allow them to cut well.

Doing it with inadequate abrasives not hard enough to cut/shape the carbides, on the other hand, will just burnish or lightly polish the carbides without shaping or thinning them, and those edges may not work so well, after the fact.
 
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