What grit is too fine for non-super steels?

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Kirk_Ferentz

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Feb 16, 2010
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I was recently in a forum seeking info about filling in some gaps in my stone lineup and one of the posters thought that I was going too high in my stones for the steels that I use. Those steels are mostly SR-101 , 1095 , Elmax , and VG-10 . I typically take them up through my Arashyama 6K and Kitayama 8K.

Am I going beyone what these steel can handle (or at least maintain for a meaningful amount of work)? Should I stop at a lower grit, say 3k?
 
Kirk_Ferentz said:
I was recently in a forum seeking info about filling in some gaps in my stone lineup and one of the posters thought that I was going too high in my stones for the steels that I use. Those steels are mostly SR-101 , 1095 , Elmax , and VG-10 . I typically take them up through my Arashyama 6K and Kitayama 8K.

Am I going beyone what these steel can handle (or at least maintain for a meaningful amount of work)?
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These steels can take super high polishing grit - many can go as fine as 50nm. As for how thin the edge can these steels go - that depend on steel grain structure & properties. A fine grain steel will support acute edge angle - retention & toughnes will depend on quality of heat-treatment to achieve targeted specs. Elmax is a high alloy fine grain steel, which can be refine/polish and support thin edge (as low as 12dps).

Should I stop at a lower grit, say 3k?
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Depend?

For an example - a woodland edge (slices + light chopping) could be freehand sharpen as folllow: set 15dps primary bevel progress to around 800 grit, 5 to 10 light strokes on 3microns to create a 20dps microbevel, 3 strokes on 1micron. Done. Add convex if seek extra edge strength.
 
Go as high as you want in grit & polish. Many will 'advise' not doing so, but that sort of input comes more from personal preference or bias, and not so much from whether the steel will perform or not. If you've already liked the results of what you've been doing, that's all the proof you need. Simpler steels like 1095, especially, can take extremely fine & highly-polished edges, and quite easily. VG-10 is excellent at high polish. Independent of the finish (coarse or polished), how thin you go with an edge is another matter, depending on whether the steel can support a thin edge or not.

It never hurts to experiment, though. Try some at high polish, and then try 'em at something coarser. Depending on what you use the edges for, you may find one better for some tasks, and another better for other tasks. That's what makes this pursuit more fun. :)
 
It was probably me that told you that.

It's based on long term personal experience with the steels mentioned and the hardness they are often found at.
 
With good HT, all the steels you listed (which vary a great deal) can take a very nice highly-polished edge. Whether or not you should apply one depends more on what you want to cut than on the steel.
 
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My experience so far has been that taking these blades through the whole spectrum of grits absolutely makes them sharper, and the edges seem to hold up pretty well, except for a few cases ... I remember one nice edge on my ELMAX blade that chipped, and there have been a few times where I thought I lost a finely polished edge pretty quickly. In other cases, though, I felt like polishing made a longer-lasting edge.

I guess I never thought that polishing would actually make the edge weaker since (from what I understand) it isn't really removing much steel and altering the the edge dimensions, it is more smoothing it out, which will make any edge hold longer. I'm still not sure I understand why, but it seems from this post like you can over do it, but it takes experience to tell.

As for which edges are best for cutting what, if any of you has a link to a good post, that would help. The only rule I remember seeing is that a coarser edge is better for field-dressing and meat cutting and a finer edge is better for wood.
 
Kirk_Ferentz said:
(...) I guess I never thought that polishing would actually make the edge weaker since (from what I understand) it isn't really removing much steel and altering the the edge dimensions, it is more smoothing it out, which will make any edge hold longer. I'm still not sure I understand why, but it seems from this post like you can over do it, but it takes experience to tell. (...)
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Exactly. :thumbup:

There's often a misconception that polishing an edge somehow makes it thinner & weaker, and part of that comes from assuming a 'fine' edge means it's more acute, as opposed to a 'fine' finish. But a 30° edge at a mirror polish is just as strong as a 30° edge at 220 grit. It doesn't get weaker just because it's shiny. There are differences in the way each cuts, but that has nothing to do with the edge being 'stronger' or 'weaker'. :)
 
My understanding is that in THEORY there is not much benefit in trying to refine a large carbide steel to a very fine grit like a razor blade because at the very edge where wear and tear takes place, the edge will degrade by carbide tearout, so even if you polish it with a very fine grit stone, the edge will degrade by having chunks of carbides falling out of the matrix, resulting in an edge equivalent to a coarser grit stone.

Whether or not this is what occurs in practice, you might want to test it yourself with real world experience and maybe take some microscopic pictures of the edges for us!

Regardless what occurs at the edge, the polishing effect on the sides of the bevel will decrease resistance and may improve cutting performance for push cutting.
 
Even with large-carbide steels, the bevels themselves (above the cutting edge) can benefit from a higher polish. On convexed edges especially, a high polish makes a convexed edge as slick as can be, when cutting tougher, deeper material that would otherwise create a lot of friction. Really makes a difference in cutting heavy cardboard, leather, wood and heavy/stiff plastics as well.
 
Hey guys,
I understand this statement under another perspective:
I carry mostly slipjoints with these steels, case cv, boker c75, SAK's, GEC 1095 and the edge retention they present is not the best on the market, so for my experience It's not worhty spend quite an amount of time going throught the diferent grits up to 8K. to losing the edge after a little work. So with this knives I usually carry a pocket sharpener diamond ceramic(DC4) and a little handmade strop.

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with these tools I achieve and maintain a shaving pushcutting sharpness with a couple of strokes.

A complete different matter is with VG-10 and superior steels, because they really thanks the polishing and they remain sharp for a while before going throught the whole process again.

Am I wrong??

Mateo
 
I was in the habit, for a while, of taking almost all of my edges up to 2000+ grit (mirror/near-mirror), using wet/dry sandpaper. Although it took more work to get it there initially, I found it was very simple to maintain that higher finish, once done the first time. For maintenance, no need to go through the entire range of grits every time; usually just a step or two back from 2000, using a sequence like 1000/1500/2000 to restore the edge. And even then, that was only done when stropping wouldn't quite do it. 90% of the time, stropping with 1 micron diamond compound on leather/wood handled it. The upside I saw, to finishing at higher grit, was that it reduced the number of passes needed, and the grit required, to maintain it at that level. AND, a big bonus, burrs produced at higher grit will always be smaller than burrs produced at coarser grits, so those are easier to clean up. Usually took no more than maybe 5 minutes' time this way. And the 'simpler' steels, like 1095, 420HC, 440A respond very quickly to re-honing anyway (I've noticed 1095 and 440A take a high polish very quickly), so that speeds the process even further. Steels like D2 and S30V will usually require a little more time to bring an edge back, once it's gone.
 
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The level of polish is irrelevant to steels for the most part, in that, with the proper sharpening gear, you can put a high polish on any steel. The question is are your cutting needs best served with a super high polish, or does a coarser finish work best. You need to be sure the abrasive you use can cut the steel and any carbides in the steel, whatever grit you use to finish your edges.
 
bluntcut said:
These steels can take super high polishing grit - many can go as fine as 50nm. As for how thin the edge can these steels go - that depend on steel grain structure & properties. A fine grain steel will support acute edge angle - retention & toughnes will depend on quality of heat-treatment to achieve targeted specs. Elmax is a high alloy fine grain steel, which can be refine/polish and support thin edge (as low as 12dps).


Depend?

For an example - a woodland edge (slices + light chopping) could be freehand sharpen as folllow: set 15dps primary bevel progress to around 800 grit, 5 to 10 light strokes on 3microns to create a 20dps microbevel, 3 strokes on 1micron. Done. Add convex if seek extra edge strength.
Click to expand...


What does dps stand for?
 
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