A note on the subject of microbevels

I had a discussion about this on another forum and i thought it might be useful here... i think people misunderstand microbevels (and also have no clue what thin behind the edge actually looks like with regard to thinning)...

microbevels are intended to achieve the following things (not necessarily all of them, but at least one, if not a combination of a couple or more):

-maintaining extremely thin geometry on a knife that could not otherwise handle it
-reduce chipping in super hard steels
-increase stability in larger carbide steels (especially at low sharpening angles)
-improve edge retention at a cost of maximum sharpness

Here is an example of very thin behind the edge:

 

She has quite a nice curve.

 

So that is what I need to aim for?

 

not necessarily this thin, but a lot of people come to me and say, "my knife is super thin behind the edge", but when i look at it, its pretty damn thick. I just put this up as an extreme example of thin.

 

This is an interesting topic for me. I shoot for .05mm on most of my blades (no more than .10mm ever) behind the edge before sharpening. This is kind of a difficult thing to measure properly to be honest...but with careful repeated efforts I figure I'm pretty accurate. How does that compare to the above blade? What is a target number that you shoot for (if you don't mind sharing!)?

I also micro bevel my knives, for edge holding purposes.

 

honestly, i dont measure... never have

 

That's actually very informative in and of itself.

I wasn't measuring at first, but I felt that I needed a benchmark, since I'm not starting with something that already cuts, if you know what I mean. My purpose is of course to give the end user a knife that doesn't need any additional work to make them happy...and the number does help me with that.

Perhaps one day when I'm at your level in the sharpening department, lol...I won't need the numbers either!

Thanks for the quick response my friend!

 

its not that there's nothing to be learned from measuring... its just that i've notice people become reliant and over-obsessed with them instead of more practical testing... i.e. just cut something and see

 

I agree completely. In my circumstances though...there's not an edge on the blade yet at all. That's the number I shoot for prior to setting the primary bevel. Which at that level of thinness, takes only a few strokes most of the time.

It's a bit different than reconditioning an already made blade I would guess...and so probably outside the realm of your intentions with this post.

 

thanks for the thread and that sexy pic jon.

 

Couldn't agree more. I think visual inspection and testing means more than the numbers.

 

I don't discount or depend on data. There are useful things to glean from the numbers if one understands them. Some important things are subtle and hard to measure, but the easy measurements can still be valuable.

The biggest problems seem to be that measurements take time and effort to make, and ignorant people are overdependent on incomplete data.

 

I've spent too much time looking into a loupe. Has someone developed standard, repeatable, cutting tests I can do with household items?

 

Many people does.

I cant tell you what is the test for household items, o_O but with knives, you can do a very repeatable test of cutting vegetables. ump
If you thinned your used and many-times-sharpened blade you have to go WOW[and I mean WOW] how much better it is after thinning, then thin 2-3 times still to get it to where you want it.
That works for most people, simply because few really bothers to put in the time and effort. If you ever do place those 20 hours to a given knife, I promise your edge will be stellar, and not because its so sharp, its because you will look after it and baby it. You will then understand that maybe a microbevel is for you, since you will not do thinning every month or two.

Its not necesarilly about how it cuts, its about your feelings of how the thing does it.

 

Cutting tomatoes and push cutting thin paper. I only use a loupe now if I think I might have a burr or wire edge I haven't abraded well.

 

Fair, but neither of those tests give the kind of objectivity I'm looking for. Something like: Cut through .5 inches of 500gr of banana when dropped from 20cm...but, you know, less stupid.

 

All i can say is you need to go produce shopping before each sharpening.

 

Correct me if I am wrong. But isn't the sharpness objective and tailored to the task? Different people have different ideas what a sharp edge is. And different tasks have different edges depending on what you want to do. That's why people keep telling me to go cut something. See how I like the edge, it's personal after all.

 

That's exactly it @Rami. I sharpen different knives to various levels depending on use as I believe you should.

 

I have a sandwich knife, probably Sheffield carbon steel, I've sharpened with 36 grit on a belt sander, then buffed with green chrome on a buffing wheel. I call it micro-serrated. Works great on po-boys.

I have a German carbon steel knife with 1/2" positive serrations I use on hard breads.

My 440c and AUS-8A knives can be steeled, but I won't do that with my VG10- or SG2-cored knives.