How to categorize my sharpness?

[hardheart]

Yeah, I've had the edge enter the paper on contact, but then not want to cut with additional applied pressure.

 

[Cliff Stamp]

Are you thinking just your sample was not hardened properly, or do you think it might be a CR wide problem?

It is hard to know without the heat treatment. Reeve leaves his angles so obtuse that you would expect the general commentary from the user base to not reflect such a problem anyway.

I dislike the stock angles now and want to go more acute but dont know what I can get away with safely and still get a workable stable edge.

What types of cutting, what materials?

and have you tried any Strider s30Vblades?

Not as of yet and it isn't likely in the future.

Cliff, maybe hardheart and I can persuade you to look into this some more sometime

This is automatic with any contention of substance. I already made a note to look at the force response to cut depth the next time I check push cutting sharpness in detail.

-Cliff

 

[gunmike1]

I borrowed Cliff's modified Fallkniven U2, which has an extremely thin and high hollow grind (~4 degree per side). I brought it from X coarse DMT to ultrafine Spyderco rods and finished on a strop loaded with CrO to completely remove the 15 degree microbevel. My average pushcutting distance was a bit over 4" from the point of hold. These were push cuts that continued all the way through the paper. I had one push cut start at 4.78" from the point of hold, but it only went maybe 3/16" deep, so I didn't factor that in to the average. The farthest out I got when I got the knife to cut all the way down through the paper was 4.26". One should note that these sharpness levels have more to do with the geometry and blade steel than my sharpening skills, and it is interesting that I got just about the same results with a 15 degree microbevel on that knife.

I have noticed several times when testing sharpness on newsprint, that at some point the knife will just initiate the cut but not be able to continue it. the paper just flops and the knife can't continue the cut.

 

[sodak]

Those are great numbers! Sometimes I have to turn the paper 90 deg as it does indeed have a "grain" to it.

Is that U2 VG10? I'm thinking about getting the same thing done on one or two of my folders, and trying to decide on the appropriate steel to grind thin, that has the necessary strength/edge stability. So far, I'm thinking of M2, 52100, or maybe VG10. I'd really like to try it with a Carbon V folder I have, as it's a laser already. Any suggestions?

 

[hardheart]

the cutting edge is SGPS. I'm waiting for Ray Kirk to contact me about a 52100 folder, and I should have something interesting with my M2 Rittergrip soon.

 

[gunmike1]

For me the "leap" from getting maybe 2.5" sharpness into the 3"+ range and even 4" with a couple of knives was all in using an incredibly light touch; I use ceramic rod sharpeners but I suspect the same principle applies regardless of method, and probably easier with an Edgepro because of the larger contact area.

I would describe the difference as almost shocking it's so subtle, just 3-4 feather-light passes is often all it takes. At first I thought this was so minimal that something wasn't right, so little extra metal would be removed after all .... and I really wondered if such an edge was any good in terms of retention, but you do see the benefits of high initial sharpness like that even after a fair amount of use.

Using light pressure and using a lighted microscope to track the burr really helped me to improve my sharpening results. Another thing I noticed was that with the Spyderco benchstones instead of the Sharpmaker rods it is easier to avoid burring, as the contact area is much larger. I lean the benchstones and the strop against the sharpmaker rods to maintain my angle for my microbevel because I still like using an angle guide, as I am relatively new to sharpening and especially freehanding on benchstones. Although, I don't bother with angle guides anymore when I'm just thinning out knives on my X coarse DMT benchstone, as that angle is only for shaping, and not sharpening, anyway.

 

[Dog of War]

Using light pressure and using a lighted microscope to track the burr really helped me to improve my sharpening results.

Same here, I started examining blades under magnification a while back and it's invaluable. Eliminates most the guesswork when it comes to sharpening and trying to resolve edge retention problems.

BTW those are really exceptional sharpness numbers. You should send one of your best blades to Cliff, maybe you'll take over first place on his sharpness list from Ben Dale. Of course I wouldn't be surprised if Ben decided to answer the challenge.

Another thing I noticed was that with the Spyderco benchstones instead of the Sharpmaker rods it is easier to avoid burring, as the contact area is much larger. I lean the benchstones and the strop against the sharpmaker rods to maintain my angle for my microbevel because I still like using an angle guide, as I am relatively new to sharpening and especially freehanding on benchstones. Although, I don't bother with angle guides anymore when I'm just thinning out knives on my X coarse DMT benchstone, as that angle is only for shaping, and not sharpening, anyway.

That all makes sense. When you break down sharpening into major two steps - cutting relief, then applying a microbeveled finish edge - the process becomes much more efficient. Pretty much the only time anymore I ever use anything between about 240-280 grit and fine ceramic is when I decide I want a slightly more robust profile, and then I just use medium ceramic to add a small secondary bevel to the primary/relief.

 

[gunmike1]

BTW those are really exceptional sharpness numbers. You should send one of your best blades to Cliff, maybe you'll take over first place on his sharpness list from Ben Dale. Of course I wouldn't be surprised if Ben decided to answer the challenge.

I highly doubt that. If Ben had the same knife he would do much better, I'm sure of it. He sharpened my Spyderco R2, with a MUCH thicker (.018" vs <.005") and more obtuse edge (12 degrees vs. 4 degrees), and when I tested it the results were very similar to what I got with the U2. He didn't put much time into for a contest, either, just a quick demo. Plus, newsprint, both the testing methods and materials, are so variable that if I used someone else's technique and/or material the results may not look nearly as impressive. I would like to do some thread testing on a scale like Cliff does for testing push cutting sharpness, it seems like a lot better way to get a consistent and true measure of push cutting sharpness.