Microbevels

Does anyone know how an edge behaves if you leave it with well toothy secondary bevel and give it a smooth micro bevel? Or vice versa? I would be interesred to know if anyone has experience with such combinations.

Thanks in advance : )))
 
I don't spend too much time working my secondary bevel. What I have been doing lately is using a guided rod setup to set a 30 degree bevel, then use the Sharpmaker to set a 40 degree micro-bevel, and use the Sharpmaker to maintain it. I am pretty pleased with the results. In theory if you polish it and make it smoother it will have less drag on the material being cut. On my micro-bevel I go with the sharpest edge I can obtain.
 
I think for your blade it may have been the steel quality? I am a bit against microbevels as I am a big fan of the normal V scandi grind and whenever I buy a new blade it always, always has a micro bevel on it. Not that I would use a factory edge with out touching it up after initial testing but it requires me to remove more steel than was necessary.

I tried out doing a full convex grind on one of my early knives and I must say the results where much better than I expected them to be. It might be an idea to try it with your blade or even one that you may have lying around for testing purposes.
 
I hope you don't mind if I add something to a thread that was started four years ago. I just joined this forum and the first thing I read was this very informative discussion on microbevels. Unless I overlooked something, there appears to be no mention of using a sharpening steel to create a microbevel. Long ago I read an article by John Juranitch from Ely, Minnesota, in which he writes a few things about microbevels. I tried them, was only mildly impressed and went back to the roughly 17-degrees-per-side free-hand method I had been using forever. Then, at a flea market, I picked up an old flat sharpening steel, basically a steel with a much flatter form and with well-worn and unaggressive grooves. The "blade" on mine is 22cm long, between 3cm and 4cm wide and about a half a cm at its thickest point.

One day something moved me to increase the angle while steeling one of my kitchen knives, and afterwards I discovered that this action had actually created a microbevel, easily seen under a 10-power magnifying glass. To my amazement I discovered that the microbevel did not appear to decrease the sharpness of my knife at all, it actually felt sharper, possibly a result of the altered edge geometry, and it continued to easily slice through everything my kitchen has to offer.

Ever since then I have been sharpening my knives as I always have, something like 17° a side, working my way through several stones down to very fine, then finishing with leather. But after using a knife in the kitchen for a while, I now run it over the surface of this flat sharpening steel, while increasing the angle considerably. Without measuring, I'd guess that I steel it at around 25° per side, certainly more than 20° and quite a bit more than the 17° I use with my sharpening stones. After all these years I now have something of a calibrated feeling in my wrist to differentiate between the two angles. The results are threefold: A highly polished microbevel can be detected under good lighting, the sharpness remains impressive, and I now haul out my sharpening stones much less often than I used to.

Your classic form of sharpening steel can also be used, but the smaller the radius, the higher the pressure that is transferred onto the edge, so it would be wise to experiment prudently. There are also old steels to be found which, if sawed though the middle at 90° and viewed from its end, have a cross-section that resembles a square. Rather than being a round rod, the sharpening steel consists of four narrow (1cm) sides with four corners, like a long square bolt. They're great for steeling all kinds of things, and due to the flatness of the four sides the pressure applied to the edge is minimal.

I admit that this "new" method has a drawback. Ever since I was a child, I have been collecting sharpening stones from around the world, and I have always loved sharpening knives, do it for all my neighbors and friends just for fun. Now, all of my nearly 200 different stones are used only about a third as often as once was the case. I may start collecting sharpening steels.

Sam
 
Very interesting. How many steelings can you get before you have to return to the stone? With my knives and/or technique, after about 2 or 3, my steeled edges don't last very long. If you haven't read Verhoeven's sharpening paper, check it out:

http://www-archive.mse.iastate.edu/...te.edu/static/files/verhoeven/KnifeShExps.pdf

It really adds another dimension to sharpening. He confirms Juranitch's steeling conclusions, but also thinks that steeling tends to "cold work" the edge, particularly burrs, back onto themselves. Interesting stuff! No matter how long I do this, I'm always learning something new. I tend to stay away from steeling, since mine are round, and the contact pressure is very high, but have had good luck with ceramic rods.
 
It depends on the knife and the kind of steel. With good-quality stainless steel kitchen knives I steel for a very long time, I suppose up to several months, before returning to a stone. I do use round steels as well, have a few pocket steels for when I'm in the woods or at the lake, and the radius there is extremely small and the pressure very high. I just steel the knife very easily, hardly any pressure but the weight of the knife. The "trick" is the much more obtuse angle when steeling than when using stones. As I said, I don't know the precise angle, but the end result is that the microbevel is minute indeed. But it's there (younger people can see it with their bare eyes, I now need a good magnifier) and it does the job indeed. I'm not splitting hairs here, just slicing through vegetables and meat and doing it very easily. I've been using this method for years and will certainly keep it up.

Friends bring me knives that I sharpened months ago (using only stones and 17° per side) and say they need another bout with my stones. Just for fun I'll do nothing more than steel them with the flat steel at "my" angle (perhaps 25°), maybe a little longer than usual, and I find that grinding off steel is nowhere near necessary.

The problem with burrs backing onto themselves arises when too much pressure is applied, and that can be avoided with this flat steel form, which spreads out the pressure quite nicely.
 
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Hi HH, and thanks for the link. I'm new here, just tuned in yesterday, and haven't had the time to look around.

Your photos are spectacular and very convincing. This is precisely my experience with steeling and something that Juranitch was convinced of way back in the 1970's. I would guess that my angle is even more obtuse than yours, if that's the right word for it. I mean that I raise the spine of the knife quite a bit higher than when working with a stone, probably even higher than you do with your steel. I do find it important to use a relatively smooth steel, nothing aggressive, yet enough to get a little grip on the edge. I found a second flat steel last year at another flea market (I live in Europe, you can find things like that here) and it is very smooth, has no grooves at all. When I use that one, I have to apply more pressure and do more passes, but it does a fine job as well.
 
Thanks, it was fun to have an opportunity like that, not everyone has a nice microscope to learn these sorts of things. I never did make steeling part of my SOP, I had too tough a time knowing when to steel, if I should have increased the angle etc. For a long time I used to maintain my kitchen knives with a coarse and fine steel, worked very well, and I still use it from time to time. On softer steel one can get an almost flawless grind pattern from a coarse steel - follow up with the fine one and you're in business. I ran into trouble on some of the higher RC blades using a steel, so I just sort of shied away from it. Massive potential with practice no doubt.

Welcome (and welcome back) to the forum!


HH
 
hello, I have Ontario rat 1 folder and there is double bevel with 17° bevel and 25° microbevel. I was thinking about reducing those 17° to 12°. What do you think?
 
hello, I have Ontario rat 1 folder and there is double bevel with 17° bevel and 25° microbevel. I was thinking about reducing those 17° to 12°. What do you think?

I'm not familiar with that knife. I don't know the thickness of the blade. First question is what do you use the knife for? Do you cut firewood (camp fire, not fireplace :)), cut cardboard or just open letters, etc.? Second, I'm thinking the angles you mention are per side. Is that right or are the angles inclusive of both bevels? I have 12 deg perside on several folders with a micro-bevel of 40 deg. I set these angles with an Edge Pro. But when I touch up I normally do that free hand and the edge angle increases slowly over time. Just for word usage clarity on my part when I say micro-bevel I'm referring to a VERY small, almost invisible edge bevel. Then as the micro-bevel gets larger after several touch ups I don't consider it micro any more and I prefer the term edge-bevel. That's just how I define the bevels. I only mention that because of the size of the edge-bevel (or micro-bevel) will determine your decision. If a 12 deg. per side (24 incl.) has a micro-bevel (VERY small or narrow) of 25 deg per side the edge will still be relatively weak if the knife is used for harder work (cardboard and harder) IMO. You may experience chipping if not cutting very straight and putting some side pressure on the edge. If OTOH, the edge bevel is wider and easily seen the edge will be stronger but the 12 deg angle will make the blade cut or slice better. As long as you aren't cutting a lot of tuf material and not using a LOT of side pressure a 12 degree per side back bevel (another term) is good. I use it quite a bit on folders. But, without a higher angle edge bevel I'd get LOTS of micro chips especially with harder steels. AUS-8, VG-10 and the like woul roll rather than chip. But with the higher edge angle I think you'll be very happy. What steel is the blade made of? Should have mentioned that first actually I guess. :) Having said that I admit I'm no expert at all. These are just my opinions at the moment. So don't listen to me as a professional. Rather another half educated about knives.

Jack
 
Well, it is AUS-8.. And yes, it was 34/50 deg. inclusive.. Im new to knifes and generally sharpening and today I discovered term "microbevel" :) I use this knife pretty much for everything.. cutting food, cardboard... I was only thinking how to make the knife cut/slice better without changing the bevel angle(25) because I like this angle on this blade(AUS-8 gets dull quite quickly).
 
I marked the blade with black marker and then I was trying various angles... :) So if I understand this correctly the narrower the microbevel is (for example 40 inclusive and less) the more suitable it is for smaller bevel? I somewhere watched a video about a guy who had like 20 deg. inclusive microbevel and 12 deg. bevel inclusive on his Spyderco and he said that this lower bevel makes his edge help to stay sharp longer..
btw. sorry for my bad english :)
 
Novaculite - what you brought up.. using a steel for a microbevel... I have a good friend, who's been a butcher for 20 years. I have a recent interest in knives, and he's been mentoring me about his sharpening methods. He (Ernie) will swear all day long, for him- sharpen on coarse or medium oilstone at 20', then steel at 30'. He claims that this edge will cut meat better and way way longer than any other method he's seen. Ernie's opinion, for butchering, is to never ever put his Victornox boning knife on a fine stone. Ernie tells me younger guys come in with super fine edges that are sharp as all get out, but are beyond steeling after 1 or 2 days, while his edge goes 4 or 5 days before it sees a stone. These guys are cutting up cows, pigs, deer.. you name it..all day long, every day.

Just thought I'd share...my first post. I'm here to learn!
 
me2- No, I sat with him last night, touching up some Bench Mades, etc at home.. at his meat store he has Forshner 10" smooth/fine combo steels, but he only uses the smooth; at home he has the smooth only.
Some of his employees will use the fine(grooved) steel towards the end of a knifes sharpness life, just before it goes back to the stone.

At work, he steels 4-6 times a day, back to a stone every 4 days or so.
And just so you all understand, why I care what Ernie does and swears by- one example of why: I've seen him take a deer: skin it, quarter it, and debone it - in 15 minutes. All with a 5" semi stiff Forschner/Victornox boning knife.
 
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