SM - coarse vs polished edge

[ZMW]

It seems the best long term edge performance comes from coarse edges for most steels. What rod/grit should I finish a 40d microbevel with? What grit are the med and fine rods?

I currently have CBN, med, and fine sharpmaker rods. Finishing my edge with the fine rod - does that still create a coarse edge, or polished?

Thanks!

[bearfacedkiller]

I wouldn't say that the fine stones give a toothy edge. The medium stones do but just barely. Grits are whacky and numbers are confusing.

My 1200 DMT seems to be in between the two and they call that extra fine. Even the Spyderco brown/medium stones seem to be finer than the 600 DMT and that is what they call fine. The 600 DMT gives a toothy edge and the Medium Spyderco is a little finer in my experience. Still a little toothy. If a coarse/toothy edge is what you are after stick with finishing on the brown rods. You can still get screaming sharp off of them.

[mattman]

There's a great chart over in the "Maintenance, Tinkering, and Embellishment" section on Blade Forums... It's stickied... Grand Unified Grit Chart?

Check it out.

[Surfingringo]

I would say that the medium sm rods still don't really provide a very coarse edge. Unlike Darby, I find the brown sharpmaker rods are notably LESS aggressive than the dmt 1200. Could be that my rods are just getting old and losing their bite? If you want a coarse finish from the sharpmaker then the best trick is to rub the corners of the brown rods together until you break through the coating. It takes about 10-15 seconds and you will feel (and smell) it happen. After doing that, the corners will give a finish similar to the dmt 1200. Just use light pressure when using the corners.

[ZrowsN1s]

I recently purchased a 22x peak loupe for checking out my edges. I found that even my finest stone 1200 grit diamond, left visible 'teeth' under 22x magnification. Only stropping produced a 'smooth' edge. Just thought I'd share. Coarse edges look pretty cool under high magnification (reminds me of the teeth on a drywall saw).

[Surfingringo]

I recently purchased a 22x peak loupe for checking out my edges. I found that even my finest stone 1200 grit diamond, left visible 'teeth' under 22x magnification. Only stropping produced a 'smooth' edge. Just thought I'd share. Coarse edges look pretty cool under high magnification (reminds me of the teeth on a drywall saw).

Hey zrown, have you by chance compared the apex left by the 1200 grit diamond to that from a Spyderco medium ceramic?

[ejames13]

I would say that the medium sm rods still don't really provide a very coarse edge. Unlike Darby, I find the brown sharpmaker rods are notably LESS aggressive than the dmt 1200. Could be that my rods are just getting old and losing their bite? If you want a coarse finish from the sharpmaker then the best trick is to rub the corners of the brown rods together until you break through the coating. It takes about 10-15 seconds and you will feel (and smell) it happen. After doing that, the corners will give a finish similar to the dmt 1200. Just use light pressure when using the corners.

Does this also work on the flats?

[Surfingringo]

I would say that the medium sm rods still don't really provide a very coarse edge. Unlike Darby, I find the brown sharpmaker rods are notably LESS aggressive than the dmt 1200. Could be that my rods are just getting old and losing their bite? If you want a coarse finish from the sharpmaker then the best trick is to rub the corners of the brown rods together until you break through the coating. It takes about 10-15 seconds and you will feel (and smell) it happen. After doing that, the corners will give a finish similar to the dmt 1200. Just use light pressure when using the corners.

Does this also work on the flats?

Yes, but to a much lesser extent in my experience. It is VERY noticeable on the corners.

[ZrowsN1s]

I recently purchased a 22x peak loupe for checking out my edges. I found that even my finest stone 1200 grit diamond, left visible 'teeth' under 22x magnification. Only stropping produced a 'smooth' edge. Just thought I'd share. Coarse edges look pretty cool under high magnification (reminds me of the teeth on a drywall saw).

Hey zrown, have you by chance compared the apex left by the 1200 grit diamond to that from a Spyderco medium ceramic?

I have not. I don't have a sharpmaker, but lately I've been considering getting one for sharpening SE blades. I've always used diamond hones, or Arkansas stones, never tried ceramic, maybe I should branch out. I can tell you that the teeth left at 1200 grit diamond are very very small.

[Brock O Lee]

For a very coarse finish, you can even try finishing on SM diamonds...

My well worn set of SM diamonds are in-between DMT Coarse (320/blue) and DMT fine (600/red) if I had to guess. They leave a micro bevel that slices *very* aggressively and stays sharp for a looong time. I've used this finish for a few months, but came to the conclusion that it doesn't give me the general push-cutting ability that I wanted, so I'm now back on SM med or DMT fine.

[chuck_roxas45]

In my experience, you can go too coarse and from what I've noticed, too coarse also looses bite fast when used on hard media like wood or harder plastics. I like a 400-600 grit edge for all around use. I usually use SiC stones for the final strokes.