I just had a light bulb just go off, sort of.

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This afternoon, actually just a bit ago I sharpened a couple of Victorinox Kitchen Knives. I had been steeling them probably for the last 8 months so I thought it was overdue for a sharpening. I thought about breaking out my Hapstone because I have read that Victorinox Kitchen Knives come 30 deg inclusive from the factory. I also know from what I read that the Victorinox are relatively soft steel? Well I decided to run them across my DMT Diamond Stones F/EF and do it free hand, something that I am getting more and more comfortable doing. Well, as you probably know the DMT worked their magic and didn’t take long at all to do their bidding. To my delightful surprise, it cut against the grain of telephone book paper, with ease. What is frustrating for me is, my Spyderco's that are 40 deg inclusive cannot cut through phone book paper against the grain (for me anyway). With the grain is no problem but against is a different story. I am thinking of taking my Spydies to a 30 deg inclusive, anybody else do this?
 
Sounds like you may not be truly apexing the edge?

Do you use a sharpie to see where you’re actually making contact?
 
Yes, but have to admit that I do not use the Sharpie 100% of the time so perhaps that is a contributing factor. I did not use Sharpie at all on the Kitchen knives. Maybe I just lucked out on the Victorinox?
 
What is frustrating for me is, my Spyderco's that are 40 deg inclusive cannot cut through phone book paper against the grain (for me anyway). With the grain is no problem but against is a different story. I am thinking of taking my Spydies to a 30 deg inclusive, anybody else do this?

Your comparison isn't equal at all. A Victornox kitchen knife tends to be very thin with (mostly) straight sections. A Spyderco blade (usually folding knives) are generally much much thicker, and are usually cut to modern folding knife shapes. Which means that they don't have long straight sections of blade like a kitchen knife will.

What you will find overall is the truism of: Thin Is Sharp. A totally dull razor knife that won't cut skin at ALL, will still slice cardboard. A PUTTY KNIFE, will cut carrots. A big tactical blade that's razor sharp (hair shaving) will take more force to cut a carrot than a putty knife.

Geometry trumps edge sharpness in many many cutting tasks. This is why terrible old kitchen knives, that couldn't possibly cut your skin still work for vegetable prep even after 20 years of not being sharpened. Thin is sharp.

You're seeing this same lesson in a different form with the phonebook paper. A thin blade that is rather sharp will seem like a freaking laser compared to a thicker very sharp blade. So kitchen knives always seem to cut phonebook paper better than the PM2 or Delica in your pocket. Because the geometry of the kitchen knife is superior.

This is why I gravitate so heavily towards Spyderco's FFG blades. Should I say it again? Yeah, I should: Thin Is Sharp.

Lowering the edge angle on your folding knives can help some. But if the blade stock is really thick, you can't meaningfully change the cutting geometry without also massively thinning the stock of the blade behind the edge. You can certainly switch to sharpening your blades with the SharpMaker in the 30 degree slots. It will probably require you to use other stones to thin the blades first. The sharpmaker alone probably won't do it.

...and the kitchen knives will still cut better until you get your folding knives very thin. Say it with me now: Thin Is Sharp.

Brian.
 
I just had a light bulb just go off
Hey yeah ? I'm sitting in the dark too . . . what a coincidence.
:)
I am thinking of taking my Spydies to a 30 deg inclusive, anybody else do this?

I would encourage even more shallow.
I call this : Normal Operating Procedure and reprofile about anything I buy. If it doesn't need it then I am pleasantly surprised.

You've seen this ?
He's right.
 
I would encourage even more shallow.
I call this : Normal Operating Procedure and reprofile about anything I buy. If it doesn't need it then I am pleasantly surprised.

So I'm not an 'Outlier', that's good to know. Thanks for sharing the video.
 
(...)What is frustrating for me is, my Spyderco's that are 40 deg inclusive cannot cut through phone book paper against the grain (for me anyway). With the grain is no problem but against is a different story. I am thinking of taking my Spydies to a 30 deg inclusive, anybody else do this?

That's what I've done with every knife I carry; literally all of them. I don't even carry them unless or until they're somewhere within that 30° inclusive limit.

If fully finished (apexed), the 30° edges will cut/slice paper and everything else much more easily. But, as has been mentioned, a 40° edge should still at least cut paper both ways (with/across the grain), so long as it's fully apexed. But the apex needs to be in pretty good shape, at the 40° geometry, to do it consistently and repeatedly. Just a little loss of apex crispness at 40°, and most fine cutting will be stopped in it's tracks. That's the advantage to taking edges down to 30° or lower, as they'll keeping doing most of that cutting, even after the apex isn't quite perfect anymore.
 
That's what I've done with every knife I carry; literally all of them. I don't even carry them unless or until they're somewhere within that 30° inclusive limit.

If fully finished (apexed), the 30° edges will cut/slice paper and everything else much more easily. But, as has been mentioned, a 40° edge should still at least cut paper both ways (with/across the grain), so long as it's fully apexed. But the apex needs to be in pretty good shape, at the 40° geometry, to do it consistently and repeatedly. Just a little loss of apex crispness at 40°, and most fine cutting will be stopped in it's tracks. That's the advantage to taking edges down to 30° or lower, as they'll keeping doing most of that cutting, even after the apex isn't quite perfect anymore.

Hello David, What would you recommend for a reprofile (Resetting the Bevel)? At what degree if the 15 degree mark I will aim for regarding the Apex. I will use my Hapstone a long with an Angle Cube so I can get pretty precise. Thanks....
 
Hello David, What would you recommend for a reprofile (Resetting the Bevel)? At what degree if the 15 degree mark I will aim for regarding the Apex. I will use my Hapstone a long with an Angle Cube so I can get pretty precise. Thanks....

With most of my knives that I've thinned out to lower angles, I've just done it a little bit at a time, going lower in small steps over a few resharpening sessions. For heavy & thick blades needing a lot of metal removed, that's worked out better for me. It keeps fatigue from being an issue, which just makes for sloppy work when you get overly tired trying to do it all at once. Usually, a coarse hone of maybe ~ 180 - 220 grit works pretty efficiently for that, or maybe a ~ 320 for thinner/smaller blades. Use a hone appropriate to the steel type, like diamond (XC/C) for high-vanadium steels, or at least a SiC stone in the coarser stages, following with diamond on those steels for refinement at Fine/EF/etc. Simpler steels in plain carbon or low-alloy stainless (420HC, etc) can be done with most anything, in aluminum oxide, SiC or diamond, according to your preference.
 
I find a better way to test a wide angle edge, 40° etc., is to try shaving curls off something. I use a single hair in my arm. If I can shave curls off it it is sharp. If the hair jumps off my arm before I get to it with the edge then it is Very Sharp. :)

I can get a 54° inclusive to shave little curls off a hair. It won't look good cutting phone book paper though.

The problem with testing wide angles on stiff material such as in the middle of the edge of paper is the sides of the material holds the apex out of the cut and the material splits ahead of it. Kind of like shown in this old drawing I made long ago.
IMG_2061.jpg
 
What is frustrating for me is, my Spyderco's that are 40 deg inclusive cannot cut through phone book paper against the grain (for me anyway). With the grain is no problem but against is a different story.
Hi,
Are you talking slicing phonebook or push cutting?
What is your sharpening procedure exactly?
Are you using the corners of the triangles? Stick to the flats :)

Not being able to push cut phonebook paper cross grains means
the edge is under shaped , its not fully apexed, the edge bevels do not meet,
and/or you have a "big" folded over burr

A few alternating strokes to stand up the burr,
then two alternating edge leading strokes per side at "double" the angle to remove burr,
should get your 20dps edge push cutting phonebook paper at 90 degrees to the paper in all 3 axis (90-90-90),
if it works that means it was a burr
if it doesn't, it means its not fully apexed, in which case do more strokes... deburr...
check this pretty good list of steps debugging for getting silly sharp with the sharpmaker
Spyderco Sharpmaker Advanced Sharpening Curriculum / Trouble sharpening super blue - Spyderco Forums

Remember to finish with ultra light passes (as much under 100 grams as you can )


I am thinking of taking my Spydies to a 30 deg inclusive, anybody else do this?
Spyderco sal himself says all their blades can do 15dps
so go for it.
if you do, consider dropping by half a degree or a degree at a time, its
Efficient grinding reprofiling with sharpmaker 1-3 minutes * 10 steps = 10-30 minutes total to drop angle from 20 degrees per side to 15 degrees in half degree steps , Reprofiling/Sharpening CPM 3V? - Page 2 - Spyderco Forums


Also, speaking of lightbulbs, consider this mind exploding material , spyderco delica/pacific salt...Extreme Regrind , ~6DPS no damage in 50 slices into pine, hardwood flooring and plywood the edge eventually gets damaged while cutting metal (steel food can)
 
Well there are 2 parts to being "sharp" - cutting the current surface of the material & traveling through the material.
So even a relatively obtuse angle can cut things - it is still a sharp edge after all. If you doubt it, you can try grabbing the wrong end of my old German chef's knives.
But a thick blade may have trouble parting the material as it is traveling through it. The blade is acting like a wedge. In fact when comparing the performance of European chef's knives to Japanese knives, that is exactly how it is described.
But vegetables are relatively crisp. That thin dull knives is mashing the vegetable as it "cuts" through, but the crispness allows it. Much more trouble with mushy things like meat. The thinness of the knife allows relatively easy travel because the sides are parting instead of pressing on the sides of the knife.
 
Hi,
Are you talking slicing phonebook or push cutting?
What is your sharpening procedure exactly?
Are you using the corners of the triangles? Stick to the flats :)

Not being able to push cut phonebook paper cross grains means
the edge is under shaped , its not fully apexed, the edge bevels do not meet,
and/or you have a "big" folded over burr

A few alternating strokes to stand up the burr,
then two alternating edge leading strokes per side at "double" the angle to remove burr,
should get your 20dps edge push cutting phonebook paper at 90 degrees to the paper in all 3 axis (90-90-90),
if it works that means it was a burr
if it doesn't, it means its not fully apexed, in which case do more strokes... deburr...
check this pretty good list of steps debugging for getting silly sharp with the sharpmaker
Spyderco Sharpmaker Advanced Sharpening Curriculum / Trouble sharpening super blue - Spyderco Forums

Remember to finish with ultra light passes (as much under 100 grams as you can )



Spyderco sal himself says all their blades can do 15dps
so go for it.
if you do, consider dropping by half a degree or a degree at a time, its
Efficient grinding reprofiling with sharpmaker 1-3 minutes * 10 steps = 10-30 minutes total to drop angle from 20 degrees per side to 15 degrees in half degree steps , Reprofiling/Sharpening CPM 3V? - Page 2 - Spyderco Forums


Also, speaking of lightbulbs, consider this mind exploding material , spyderco delica/pacific salt...Extreme Regrind , ~6DPS no damage in 50 slices into pine, hardwood flooring and plywood the edge eventually gets damaged while cutting metal (steel food can)



Thank you for your reply. I think the biggest battle was not properly deburring. I did take my Delica down to 17 deg but like some folks have reported that I should had been able to slice phone book paper cross grain with a 20 deg dps. So when I was sharpening my Delica the second time around I was using my Hapstone. On the final stone, prior to using my honing stone I laterally moved my 1200 gr SiC Stone across the blade edge to remove the burr. I think this a lone might had been the crux of my problem.

Interesting news about the Spydie taken down to 6 dps, wow....
 
Last edited:
Thank you for your reply. I think the biggest battle was not properly deburring. I did take my Delica down to 17 deg but like some folks have reported that I should had been able to slice phone book paper cross grain with a 20 deg dps. So when I was sharpening my Delica the second time around I was using my Hapstone. On the final stone, prior to using my honing stone I laterally moved my 1200 gr SiC Stone across the blade edge to remove the burr. I think this a lone might had been the crux of my problem.

Interesting news about the Spydie taken down to 6 dps, wow....
 
Hi,
Are you talking slicing phonebook or push cutting?
What is your sharpening procedure exactly?
Are you using the corners of the triangles? Stick to the flats :)

Not being able to push cut phonebook paper cross grains means
the edge is under shaped , its not fully apexed, the edge bevels do not meet,
and/or you have a "big" folded over burr

A few alternating strokes to stand up the burr,
then two alternating edge leading strokes per side at "double" the angle to remove burr,
should get your 20dps edge push cutting phonebook paper at 90 degrees to the paper in all 3 axis (90-90-90),
if it works that means it was a burr
if it doesn't, it means its not fully apexed, in which case do more strokes... deburr...
check this pretty good list of steps debugging for getting silly sharp with the sharpmaker
Spyderco Sharpmaker Advanced Sharpening Curriculum / Trouble sharpening super blue - Spyderco Forums

Remember to finish with ultra light passes (as much under 100 grams as you can )



Spyderco sal himself says all their blades can do 15dps
so go for it.
if you do, consider dropping by half a degree or a degree at a time, its
Efficient grinding reprofiling with sharpmaker 1-3 minutes * 10 steps = 10-30 minutes total to drop angle from 20 degrees per side to 15 degrees in half degree steps , Reprofiling/Sharpening CPM 3V? - Page 2 - Spyderco Forums


Also, speaking of lightbulbs, consider this mind exploding material , spyderco delica/pacific salt...Extreme Regrind , ~6DPS no damage in 50 slices into pine, hardwood flooring and plywood the edge eventually gets damaged while cutting metal (steel food can)

Thank you for your reply. I think the biggest battle was not properly deburring. I did take my Delica down to 17 deg but like some folks have reported that I should had been able to slice phone book paper cross grain with a 20 deg dps. So when I was sharpening my Delica the second time around I was using my Hapstone. On the final stone, prior to using my honing stone I laterally moved my 1200 gr SiC Stone across the blade edge to remove the burr. I think this a lone might had been the crux of my problem.

Interesting news about the Spydie taken down to 6 dps, wow....
 
This afternoon, actually just a bit ago I sharpened a couple of Victorinox Kitchen Knives. I had been steeling them probably for the last 8 months so I thought it was overdue for a sharpening. I thought about breaking out my Hapstone because I have read that Victorinox Kitchen Knives come 30 deg inclusive from the factory. I also know from what I read that the Victorinox are relatively soft steel? Well I decided to run them across my DMT Diamond Stones F/EF and do it free hand, something that I am getting more and more comfortable doing. Well, as you probably know the DMT worked their magic and didn’t take long at all to do their bidding. To my delightful surprise, it cut against the grain of telephone book paper, with ease. What is frustrating for me is, my Spyderco's that are 40 deg inclusive cannot cut through phone book paper against the grain (for me anyway). With the grain is no problem but against is a different story. I am thinking of taking my Spydies to a 30 deg inclusive, anybody else do this?

Over time I've reprofiled all of my Spyderco knives to 15 DPS/30 inclusive and had no problems with normal use. Once in a while I've asked the knife to do a task it wasn't meant to do or hit a staple breaking down boxes, etc. and those are the only occasions where I've had appreciable edge damage; this is not something that I think would change if I sharpened to a more obtuse angle. In short, 15 DPS should be fine for most of their offerings unless. As a point of reference, I have a Cold Steel Recon which was reprofiled to 25 DPS/50 inclusive... it will still push cut phone book paper across the grain.

My guess, as others have already said, is that you're not hitting the apex of the edge correctly or fully. Use the sharpie trick to confirm.
 
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