Your experience sharpening super steels?

I use diamond and CBN stones and rods and have had no issues with any steel (ZDP189, S30V, S35VN, S90V, S110V, M390, M4, 4V).

Yes, some require tweaking your technique, but it's no biggie, if you stick to basics.
 
I prefer silicon carbide or diamond up to about 800 ANSI, both will work. After that for further refinement I switch over to diamond.

I have gotten acceptable results using SIC all the way up to the 3 micron range but it doesn't work as well or as reliably as diamonds, especially if touching up a worn edge.

YMMV
 
Silicon carbide works but diamonds make life so much easier when dealing with some of these steels.
 
The super steels can be a pain to sharpen...because they are so durable. I was sharpening a Strider SNG for a customer a couple months ago. It took me about 20 minutes to sharpen and strop on my Lansky set up. It wasn't that big of a hassle but I did notice a distinct difference. Yet that very same durability means it won't need to be sharpened for a long while.
 
I hate sharpening these new super steels. Why? Because I was collecting knives before they were popular.

I wonder when the knife world will want to go back to a soft steel? I wish one day that would all take a turn in the other direction.

I remember my old Gerber in the 80's was so hair popping sharp because it only took a couple licks on the V-sticks. I don't know what the steel was and they did not give out that info.

I knida miss that kind of "sharp" on a knife because I want ti USE my knives and not worry about cutting on a plate of food and have to sit on a sharpener. I wish we had the same knives today (liner locks, frame locks, tactical knives ect) but with the soft steel. They would be cheaper too!
 
pathwinder14 said:
The super steels can be a pain to sharpen...because they are so durable. I was sharpening a Strider SNG for a customer a couple months ago. It took me about 20 minutes to sharpen and strop on my Lansky set up. It wasn't that big of a hassle but I did notice a distinct difference. Yet that very same durability means it won't need to be sharpened for a long while.
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You cut your steak or vegetables on your porcelain plate and have to sharpen it again. Who ever came up with this whole superstell idea for EDC knives?

Oh that's right,.. we need to use dinner knives for that and or use wooden plates because that is not what a knife is meant for.

That is the response I expect from the new supersteel generation.
 
colubrid said:
I hate sharpening these new super steels. Why? Because I was collecting knives before they were popular.

I wonder when the knife world will want to go back to a soft steel? I wish one day that would all take a turn in the other direction.

I remember my old Gerber in the 80's was so hair popping sharp because it only took a couple licks on the V-sticks. I don't know what the steel was and they did not give out that info.

I knida miss that kind of "sharp" on a knife because I want ti USE my knives and not worry about cutting on a plate of food and have to sit on a sharpener. I wish we had the same knives today (liner locks, frame locks, tactical knives ect) but with the soft steel. They would be cheaper too!
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What do you use to sharpen your knives?
 
I do them all the same on my KME with the diamond stones. Just takes a "few" more strokes with the harder steels. But.....(there's always a big but in the room. ;) )...the better steels seem to last much longer between touch-ups. And still touch up just fine on something like the Sharpmaker. Especially if the bevels are set perfectly in the first place. In fact, once I got better at setting the primary bevels on the KME in the first place, most knives now just see a strop between the infrequent Sharpmaker touch ups. And it's now extremely rare that I ever have to go back to the KME on the modern steels.
 
DeadboxHero said:
What do you use to sharpen your knives?
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I use the Sharpmaker.

It's not the sharpening system that is the problem. A softer steel is super quick to sharpen and only takes a few strokes to keep hair popping sharp. With my high ends steel, I don't even want to cut a piece of food on a plate because I know I have to spend X amount of time more getting it back to popping sharp. Problem is cheaper steels come with knives that are not well made.. have poor fit and finish and don't use materials like titanium handles ect. In other words I would like to see a softer SS in a high quality knife. That's all.
 
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I'm using the edge apex pro with natural stones and no problems with supersteels.
In emgineering they said any abrasive works, you might just need a bit more of some.
 
Jens, some say that natural stones won't work. But you're getting good results. I use SiC and India stones and some say those don't work on high vanadium steels.? DM
 
David Martin said:
Jens, some say that natural stones won't work. But you're getting good results. I use SiC and India stones and some say those don't work on high vanadium steels.? DM
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Coarse Aluminum oxide (around 100-300 grit) will sharpen the most wear resistant steels because it has very little interaction with the Vanadium within the steel even though Vanadium is harder than Aluminum Oxide, Silicon Carbide, and way harder than any Natural stone. Because the abrasive is so much larger than the carbides it just scoops them out with the rest of the steel matrix.

As the abrasive gets finer the problem with abrasive hardness becomes more apparent and an actual problem in sharpening. The abrasive starts to equal the Carbide size and because it's not hard enough to cut through it the result is the Carbide dulling the abrasive making it polish the bevel excessively and lose cutting ability. The edge will "sharpen" but it will be lacking in many areas because of the inferior abrasive.
 
Jason B. said:
Coarse Aluminum oxide (around 100-300 grit) will sharpen the most wear resistant steels because it has very little interaction with the Vanadium within the steel even though Vanadium is harder than Aluminum Oxide, Silicon Carbide, and way harder than any Natural stone. Because the abrasive is so much larger than the carbides it just scoops them out with the rest of the steel matrix.

As the abrasive gets finer the problem with abrasive hardness becomes more apparent and an actual problem in sharpening. The abrasive starts to equal the Carbide size and because it's not hard enough to cut through it the result is the Carbide dulling the abrasive making it polish the bevel excessively and lose cutting ability. The edge will "sharpen" but it will be lacking in many areas because of the inferior abrasive.
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So that problem would only be with the finer abrasives as in high grit numbers?
From which grit number up would you suggest to abstain from natural stone?

Just checked. Seems my edge pro stones are made from aluminum oxide and silicone carbide. Would that explain my good results?
 
S30v. Not easy to sharpen, dulls quick.
S35vn. Same, but harder to sharpen (longer).
Cts204p. Easy to sharpen and holds an edge long time, probably my favorite steel for a folder.

I'm a traditional wet stone user.
 
Jens Schuetz said:
So that problem would only be with the finer abrasives as in high grit numbers?
From which grit number up would you suggest to abstain from natural stone?

Just checked. Seems my edge pro stones are made from aluminum oxide and silicone carbide. Would that explain my good results?
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Good results? That's subjective, your good and my good could be two completely different things.

Up to about 1000 grit JIS most stones will cut most steels, beyond that it gets complicated as alloy content, HT quality and hardness all start playing into what works and what does not.
 
Jason B. said:
Good results? That's subjective, your good and my good could be two completely different things.

Up to about 1000 grit JIS most stones will cut most steels, beyond that it gets complicated as alloy content, HT quality and hardness all start playing into what works and what does not.
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Oh cool. Thank you.
Coincidently 1000 is all I go up to with every steel and they all shave arm and face.

Going higher than 1000 with the wrong stone would then mean it becomes duller again or just not as sharp as it could be?

Thank you.
 
I mean no offense, its just I have found over the years that what most think is sharp is on the duller side of my Sharp. I also tend to see defects in the edge most miss.

It starts out acting like it is sharpening but as you try finishing up with the stone the edge seems duller that it should be along with a small burr that just won't go away. You can get a glassy feeling or simply too much edge polish for the sharpening grit... If you're using a 1000 grit stone and getting a 4000 grit polish something might be wrong. You could say not as sharp as it could be or similar to a rounded edge.
 
It's all about the relative hardness of the material. Hardened steels come in at 7-7.5 on the Mohs hardness scale, even super steels. Carborundum and Silicon Carbide come in at 9. Natural stones will work just fine so long as you know the hardness of your stone. The same goes for manufactured stones. Being mostly ceramic, they inherently have a hardness of around 7 but contain abrasive inclusions like powdered metal and clay. The over all hardness of the stone doesn't matter because it is just a binder for the abrasive inclusions. Diamond plates (with diamond being a 10 on the scale) are a no brainer.
 
pathwinder14 said:
It's all about the relative hardness of the material. Hardened steels come in at 7-7.5 on the Mohs hardness scale, even super steels. Carborundum and Silicon Carbide come in at 9. Natural stones will work just fine so long as you know the hardness of your stone. The same goes for manufactured stones. Being mostly ceramic, they inherently have a hardness of around 7 but contain abrasive inclusions like powdered metal and clay. The over all hardness of the stone doesn't matter because it is just a binder for the abrasive inclusions. Diamond plates (with diamond being a 10 on the scale) are a no brainer.
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'Super steels' wouldn't be 'super steels' without the carbides that make them so. The carbides in super steels are WAY, WAY harder than Mohs 7-7.5; more like Mohs 9+, in the case of vanadium-heavy steels (30V, 90V, 110V, etc). Natural stones of any kind won't touch that, as they're nowhere near hard enough to abrade those carbides, and therefore will stop working as the carbides get in the way at finer grit levels. Even at very coarse grit, lesser abrasives won't cut or shape the carbides and will instead just scoop them out of the matrix steel, limiting how refined the edge can be made. At finer grit, the less-hard abrasive is no longer big enough to dig down between the carbides, which means it only 'skates' across the carbides without cutting them, and effectively stops working.

The Mohs reference for hardness is misleading as well. Being a unitless scale and instead simply an ordinal one, Mohs doesn't indicate the true degree of hardness difference between materials, instead only indicating that one is ranked harder than the next lower on the scale, no matter how wide the actual hardness gap is between them. It's the same type of ordinal ranking as might be seen in posted race results, only indicating the finishing place of each contestant (1st, 2nd, 3rd,..., 8th, 9th, 10th, etc), regardless of how fast or slow each was.

On a scale of actual measured differences, when comparing basic steel hardness to the hardness of the carbides, simple hardened steel with no hard carbides is about 600-800 on the Knoop scale. Vanadium carbides are around ~2800 Knoop - that's at least 300-400% harder than the simple hardened steel. Even 'softer' carbides, like chromium carbides in steels like D2 and ZDP-189, are nearly 2X as hard as the steel matrix at Knoop ~1300 or so. Natural stones, like Arkansas stones, are no harder than ~ 825 Knoop (the hardness of the novaculite natural abrasive in them).

A more meaningful hardness comparison, for reference:

Basic, hardened cutlery steel w/no hard carbides: ~600-800 Knoop
Novaculite (Arkansas stones): ~825 Knoop
Chromium carbide (D2, ZDP-189 are very heavy in it): ~1300 Knoop
Tungsten carbide (carbide pull-through sharpeners, also found in some cutlery steels): ~1400 Knoop
Aluminum oxide ('corundum' or 'Alumina'; Norton 'India' stones, and most ceramics of alumina): ~2100 Knoop
Silicon carbide ('carborundum'; Norton 'Crystolon' stones, wet/dry sandpaper): ~2600 Knoop
Vanadium carbide (significant in S30V/90V/110V steels and many others like them): ~2800 Knoop
CBN ('Cubic Boron Nitride'): ~4500 Knoop
Diamond: 7000 Knoop


David
 
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