How to do micro-bevel on mirror polished knives?

Joined
Nov 2, 2019
Messages
9
How to do micro-bevel on mirror polished knives?
  1. Finish the whole progression on a secondary bevel and then start with micro-bevel?
  2. Once micro-bevel is done - do I return for secondary bevel touch-up?
  3. What is the recommended starting grit for micro-bevel? How far I polish micro-bevel? Same level as secondary or stop earlier to avoid getting to mirror?
I tried following on one of my cheap knives with 8Cr13MoV steel (CRKT Pilar) with Wicked Edge Go:

Secondary bevel at 18° per side:
  • Diamond 200➜600➜800➜1000➜1500➜2200➜3000
  • Ceramic 1.4 μm ➜ 0.6 μm
  • Diamond Lapping Film 9 μm ➜ 3 μm ➜ 1.5 μm ➜ 0.1 μm
Micro-bevel at 22° per side:
  • Diamond 3000
  • Diamond Lapping Film 9 μm
Unfortunately, the knife is not that sharp - you can shave the hair on your leg and easily cut through receipt papers, but not hair-splitting sharp. Slightly visible scratches under mirror polish.

Few lessons learned from my side would be probably:
  • Less pressure when going through progression to avoid deep scratches
  • More careful when applying micro-bevel to make even micro-bevel
Any other suggestions? I really want to learn how to make my knives beautiful and sharp!

P.S. I have posted the same post in few other places (specifically Edge Snobs Facebook and Wicked Edge forum) to gather more feedback on this topic, so if you have seen this somewhere else and looking to answer - you can comment anywhere you like.

P.P.S I read previous thread on this topic which had a lot's of great replies: https://www.bladeforums.com/threads/microbevels.634739/
 
Last edited:
I always do the micro-bevel last, and generally only use my 5 micron stone then strop if I wish. 5 micron is the finest stone I use on steel.
 
Most of my knives are sharpened at #150 diamond and then refined with DMT EEF at a slightly raised angle.
I also used DMT EEF on a few edges finished at 1 micron diamond and found that it makes the edge very aggressive with a microscopic secondary bevel, which did not ruin the look of the primary bevel.
 
What are you trying to achieve with the micro-bevel? Were you unhappy with the performance of your primary bevel?

When you bring that 3k diamond paddle in at 4 degrees off the bevel angle, you hit the apex with essentially no contact area (and therefore extremely high pressure) and you shred the steel at the apex. There's nothing wrong with that, if your goal is a coarse, draw-cutting edge, but don't expect it to behave like a razor.
 
Yes, if the 'sharpness test' is all about splitting or whittling hair, then there's not much benefit to adding the micro at all. Literal razor sharpness is all about the thin (very acute) edge geometry with the narrowest apex possible. Adding a microbevel will make it less razor-like. For reference, a true straight razor used for shaving will have an extremely thin & acute edge, at or below ~ 15° inclusive (7.5° per side) most of the time. For EDC knives, anything above 30° inclusive at the apex isn't going to be ideal for shaving sharpness anymore, much less for hair-whittling. It can do it when the edge is perfectly finished; but it won't work once the edge is even the slightest bit worn or rounded. It's gets a bit easier to sustain some shaving sharpness when the apex goes below about 25° inclusive.

On the other hand, if a little more durability is desired on a thinly-profiled edge for more typical EDC uses (paper, cardboard, carving wood, etc), then a microbevel could sometimes help.
 
Last edited:
There are two advantages to a microbevel: 1) It is far easier and faster to sharpen; and 2) it improves edge stability, allowing you to use a more acute and lower drag main bevel.

If you do it right, you are not likely to see the microbevel on the mirrored edge, so there is no need to mirror it. And mirroring the microbevel would take away from the first advantage.

I'd use very light pressure on a fine-grit stone/ceramic -- just enough to raise and remove a slight burr. The Sharpmaker works well for this -- the 40 degree inclusive angle should set a microbevel on your 36-degree inclusive main bevel. Then gently strop at .5 microns. You'll be done in a minute, and you'll still have the mirrored main bevel.
 
>What are you trying to achieve with the micro-bevel?

CRKT Pilar has 8Cr13MoV steel. So I had two reasons - ease of touch-ups and strength of the edge to protect from rolling/chipping. This is essentially my EDC knife which I don't want to be afraid to use and sharpen.

>For EDC knives, anything above 30° inclusive at the apex isn't going to be ideal for shaving sharpness anymore, much less for hair-whittling.

I start to grok that with 44° inclusive (22° per side) I should not expect whittling hair. By the way here is the pic of the result where I tried to capture micro-bevel and small scratches on mirror polish from not being patient enough: https://imgur.com/a/vVoD5pY

I didn't go lower than 18° for secondary bevel since the grind is very thick so secondary bevel on anything below 18° seems too wide.
 
Last edited:
>What are you trying to achieve with the micro-bevel?

CRKT Pilar has 8Cr13MoV steel. So I had two reasons - ease of touch-ups and strength of the edge to protect from rolling/chipping. This is essentially my EDC knife which I don't want to be afraid to use and sharpen.

>For EDC knives, anything above 30° inclusive at the apex isn't going to be ideal for shaving sharpness anymore, much less for hair-whittling.

I start to grok that with 44° inclusive (22° per side) I should not expect whittling hair. By the way here is the pic of the result where I tried to capture micro-bevel and small scratches on mirror polish from not being patient enough: https://imgur.com/a/vVoD5pY

I didn't go lower than 18° for secondary bevel since the grind is very thick so secondary bevel on anything below 18° seems too wide.
Any other suggestions? I really want to learn how to make my knives beautiful and sharp!

I think ToddS' answer on the "hair-whittling" informs that aspect. You can get a blade hair-whittling sharp at 22-dps BUT you need a well refined apex - without that, you won't get it at 15-dps either.
What are you trying to achieve with the micro-bevel? Were you unhappy with the performance of your primary bevel?

When you bring that 3k diamond paddle in at 4 degrees off the bevel angle, you hit the apex with essentially no contact area (and therefore extremely high pressure) and you shred the steel at the apex. There's nothing wrong with that, if your goal is a coarse, draw-cutting edge, but don't expect it to behave like a razor.

I echo ToddS' question - what are you trying to achieve? You mentioned EDC use and ease of touch-up. The best way to make touch-up easy is to start with a thinner edge. If the edge-bevel at <18-dps seems 'too wide', then there is a problem with the primary grind on the knife, it is already too thick unless intended for VERY abusive tasks. How thick is the blade at the edge-shoulder? For my use, an EDC blade should have a behind-the-edge-thickness <0.5mm (0.020", preferably max 0.015"). At that thickness, your edge bevel at 15-dps will be <1mm wide. If that is not possible, you are using an axe, and you may want to consider a full re-grind or a different knife altogether, my $0.02.

Here is an image of a Muela PIK-AS with the edge-shoulder knocked down from 0.035" to 0.010" - cutting performance jumped SUBATANTIALLY and it can now be touched-up with ease at a thinner edge angle than previously:
P1020585.JPG



If you love the Pilar but think it doesn't cut well because of the thick grind, imagine what it would be like after Josh @razor-edge-knives got through with...https://www.instagram.com/razoredgeknives/
 
I have measured how thick is a blade at the edge of the shoulder on my Pilar - 0.85mm :)
 
Last edited:
I love the Pilar and was considering if this is worth investing into this knife. After some thoughts I decided that best I can do are two things:
* Buy BladeHQ exclusive with S35VN and Carbon Scale and add phosphorus bronze washers
* Buy micarta scales for the regular one + bronze washers

Given that first option is not available at the moment - I went with second one.

Miserably failed in another sharpening attempt of Pilar yesterday:

1. Started very gentle from 800 grit diamond stone
2. Everything was good up to 0.6micron ceramics
3. When I went further to lapping films attached to a glass platens - I was too tired and it was already late.
4. I started pushing too hard to go faster and end up introducing tons of scratches when glass platter was accidentally hitting the edge :(

Silver lining was that being gentle at the beginning and stropping with 9 micron lapping film after creating micro-bevel using 3000 grit diamond stone made super sharp knife! Way sharper than a first take )

I spent 4 hours yesterday on this - will this time get better with experience? What is the estimated time to mirror polish with micro-bevel from factory edge without reprofiling?
 
Back
Top