Any of you knife guys achieve maximum sharpness on your cutlery?

As in no amount of fine stones, leather stroping etc. seem to get an edge any sharper?

I have several that are really sharp, but no amount of extra time on them seems to get them any sharper....sort of a point of diminishing returns.

Thanks everyone!

Randy

Maybe I'm missing something here, but why would a knife need to be sharper than "really sharp"?

Just add another really without doing anything.

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Thirty characters. Exactly...

When it has a smooth edge and shaves arm hair.........Nuff done.

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S&W Accumulator

Depends on the cutlery. Specific steels and heat treats should get much different treating. Sharper dulls faster. If it won't stay sharp a long time, extra steps aren't worth it.

Carbon steels should get a honing and be good until it needs it again. Super sharp carbon doesn't stay super sharp long enough to justify it, but a honing rod can make it scary sharp in the blink of an eye.

Fancy steel will stay super sharp for a good while, and a strop sets it right back. Stone, then hone, then strop. If the strop doesn't work, try a hone and strop. If it actually got dull, do all three. Stropping brings back OP steel real fast.

Cheap stainless gets NOTHING. Diamond stone it and it can burn in hades. It will only ever be good enough.

when I was young I spent hours working on my Marine fighting knife super shave the hair sharp.. but I don't have the time for such any more.. if it can't keep an edge it isn't worth owning...

How does one quantify "sharpness"?. I have some really sharp knives that I can't get any sharper. If it cuts without sawing at it, I'm good.

My Lansky gets my knives sharp enough.
Interesting is the cheapest knife I have is a Opinel that keeps an edge with the best of them.

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Only difference Fool/Mule-ears

Some clarification of my OP....I have a set of Kershaw Kitchen Cutlery that I can get three of the knives very sharp, the others simply won't cross that same threshold.

Same manufacturer, same steel...I would be thrilled to have ALL of them respond the same.

Hope that helps clarify my question.

Randy

Looking at steel knife edges under powerful magnification explains a lot about how sharp a knife can get, and stay. Google searches for such photos and even some YouTube vids explain it pretty well.

Define your need for sharpness. Identify the steel, profile and process that will get you there. Pay your money.

I have a small box stock 10-year old CRKT M16 folder that has never been sharpened by me, and it is still scary sharp.

I carry a Kershaw for every day work that dulls quickly and gets OK sharp. It needs ceramic rod honing and stropping once every 10 days (a dozen or so uses). I can’t get it super sharp. Extra effort isn’t worth it. It does what I need it to do, cutting open boxes and envelopes, cutting line, general purpose stuff.

I have a Cold Steel dagger that seems to lose its good edge every few months by sitting in the sheath without use. A little stropping and it’s GTG, although it is my defensive carry knife so I don’t use it to cut anything. That’s a little strange. It’s plenty sharp, but the blade is thicker than the CRKT mentioned above. The thinner profile can get sharper but is not as robust. Trade offs.

ETA referencing your clarification post. Do the difficult to sharpen knives have different edge profiles (likely), or are the blades thicker? It may be worth it to take them all to a professional sharpener and have them all ground the same and then have him tell you how to keep them sharp.

If I can shave my arm hair it's sharp enough. Some kitchen knives work better with a slightly ragged edge.

Major differences in steel alloys, carbon vs. stainless, grinding pattern (saber vs. hollow-ground), heat treatment methods.

I have a couple of older Buck knives that will take and hold an edge very well, but they require some work and close attention. I also have several utility-grade knives by Chicago Cutlery and Old Forge (maybe $5 each) that do all of my big game chores. 4" utility blade, 6" boner, 8" butcher, all made for the mass market, carbon steel with slab wood handles. Probably outlive me by a hundred years.

I have hard, medium, and soft Arkansas stones. I have a good set of crock sticks. I have also acquired a great Wusthoff diamond steel, about 10" length, that will restore a "working" edge on just about any decent blade in under a minute. Not razor sharp, but very usable, and followed by the crock sticks to polish the edge there is seldom any need for more work. I keep one in the kitchen and one in my knife roll for field use.

My daily use pocket knife is a Gerber lock-back for the past 20 years. Holds a decent edge for months at a time. I also have a Boker automatic, AUS-8 stainless hollow-ground, that always seems to need attention. My 30-year old Leatherman multi-tool has a wicked sharp clip-point blade that I have never had to touch up.

I have not found a single method that works for every type of blade or use. The Wusthoff diamond steel and crock sticks have become my usual method, and it has been a long time since I have agonized over the Arkansas stones for hours at a time.

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Life of the party until 8:00PM

How sharp you can get it depends on how hard the blade is. But the sharper it gets, the faster it gets dull. With steel blades it is always a trade off between sharpness and durability. German cutlery is not as sharp as Japanese, but it holds an edge better. They are different styles of knives and are used differently. Ceramic blades are much harder than steel and you get them much sharper. But they are very brittle. You have to be very careful with them. They don't actually get dull. What happens is you get tiny chips on the edge. Absolutely nothing is sharper than a diamond blade. Problem is that they quite expensive and extremely fragile.

Sharp is sharp.

We used to say RIGHT WITH EVERSHARP!

You have to be older to get that.

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Come and take it!!

Sharpness is a difficult concept to define, much less get a full understanding of. Variables include the angle of the edge, the grind of the blade, the thickness of the blade (particularly behind the edge), the heat treat or tempering of the blade, the size of the carbides in the steel, the type of steel. A polished edge is usually considered a sharper edge, but for some uses, a toothy cuts better. How long do you need the knife to hold its ultra-sharpk edge. If that edge goes away, what o dou have, a good working edge, or just a dull knife.

I have seen demonstrations of blades that will not only shave the hair off your arm, but can also shave slices off that hair, literally splitting hais.
There are blades that can be batoned through a steel nail or a concrete block without more than minimal damage. Some blades are tough, will roll instead of chip, while others will stand up better, to a point, but will chip rather than roll when they do fail.

I can get most of my knives (not all) to shave hair off my arm. Some of them will hold that sharpness better than others. For most of my purposes, a knife doesn’t have to be that sharp to do what I need. That is a good thing, because my skills are meager, and I don’t have the patience to put a highly tuned edge on my blades.

I do most of my sharpening with a Work Sharp guided field sharpener, a $30 manual device about the size of a large harmonica. It has two diamond-embedded steel plates, a ceramic rod, and a strip of leather for stropping. I also get a lot of use out of a leather-faced paddle strop.

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Not in jail.

I have several Old Hickory kitchen knives that are easy to sharpen and stay sharp. Old carbon steel knives last a long time without any problems.

Lansky will make just about any knife shaving sharp. Carbon steel, stainless, etc. one of my best investments for knife sharpening. I have worn out several sets over the years. I had several fellows try and teach me how to sharpen while in the service. The Lansky makes it fairly easy.

Regards, Rick Gibbs

I had a camilus no 4 grind ,I think it was
I used a stone then ceramic rods then leather strop with jewellers rouge
Then hours on denim .
The kind of time only teenagers have lol
The edge was so polished there was no discernible ground edge
That knife was quite literally sharper than a razor
It was a knife that drew blood on many people that tested it’s edge by rubbing their thumb print on it
In the tenth grade that knife made the rounds in my science class as it could produce blood more easily and with less pain than the lancet in the finger , make a fist and gently bump your tightened knuckle with the edge and it would cut
I was picky about what I would cut with that knife as the edge was so fine it could be easily damaged
That knife was scary sharp , honestly doubt a knife could be any sharper
That knife was lost years ago , now I can’t be bothered to strop my pocket knife ceramic rods are good enough

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the rules? there are no rules

I'm not a deep enough thinker to sit and ponder things like sharp , twice as sharp , maximum sharp .
When the knife gets dull ... I pull out the old butchers steel , hit it a few strokes and when it's sharp ... I stop .
Heck Fire ... I never learned how to measure maximum sharpness ... I don't even have a maximum sharpness tester ... when a blade shaves hair off my arm ... it done ! That's the way Dad and Granddad taught me ...sometimes ignorance is bliss and sharp is sharp .
I use a butchers steel followed by ceramic stick (shaped like a butchers steel but ceramic)
Matbe I need to get Doug Marcaida to test them for me !
Gary

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NRA Member

I have a 50 year old Gerber steel I bought with a couple of Gerber kitchen knives, well 50 some years ago. A paring or utility knife and a chefs knife. They held an edge well if kept oiled but they were a sandwich steel with carbon steel in the middle that would quickly rust. I guess they were brittle too as I dropped the chef knife once and the blade cracked. Also the handles on the knives and steel were chromed and were too slick. I no longer have the chef knife as it broke but the paring knife is around somewhere, I think.

The point of it is the steel was a very aggressive and very hard. It shows wear now and isn't as aggressive as it was but it will still quickly bring most any knife back to a low grade slightly ragged shaving sharp in short order. I can then finish the blade off with a finer steel and if I have the desire I can finish off with a totally smooth polished steel.

If I can't bring the edge back with that 50 year old Gerber steel then it's time for the stones, which I have plenty of. I have a Lansky guided stone set somewhere and it will produce a factory edge but I learned long ago how to keep consistent angles on my edges by eye and the Lansky set is too slow. I do keep a pretty steep angel for a longer lasting edge.

I also had a Gerber lockback folder of the same vintage. It had reddish wood scales (redwood?) which were a little fat but it had the same sandwich steel. I lost that one somewhere and still regret it. The model would probably have collector value now if it wasn't too worn, which it would be.

Lately I've been carrying a $20 Chinese Gerber liner lock. It holds an edge well enough, is easy to sharpen and is the perfect blade style and size for me. Thin, with aluminum scales, and about a 3 3/16" mild drop point blade, plain edge with a pocket clip. I think it's an Air Ranger but it seems they may have changed a bit. It might be similar to the Benchmade Mini Bugout but much more expendable. Yeah, I'd prefer it wasn't Chinese.

Sorry about getting long winded.

A major point to consider is the bevel of the edge. Standard American cooking knives use a 20 degree bevel; high-end European and Japanese cooking knives use a 15 degree bevel; straight razors are best when "hollow ground" where both sides of the bevel are concave and meet at an incredibly small angle. By the way, a hollow grind is incredibly difficult to do and requires a lot of skill and preferably a full set of VERY large grinding and honing wheels. And unless you are willing to frequently deal with edge chipping and other issues like that, utility and work knives should have a wider bevel on their edge than a cooking knife.

While tools and technique are important, another big factor is the blend of steel that the blade is made from. Some steels can be sharpened very fine but won't hold the edge for long; others are very difficult to sharpen but will hold their edge much longer. I have a collection of straight razors and can tell you that high-carbon steel blades are more difficult to hone and strop that stainless steel, will hold their edge longer, but don't resist staining or rust. It's a give-and-take.

The last thing I can offer is learn to use a STROP (not strap!). It's a length of smooth, well-finished leather that literally polishes the bevel of your blade to smooth out even the finest grinding marks. Barbers used to use them to hone their straight razors, but now most states have banned multi-use razors in favor of ones with a single-use replacement blade.

I can get a piece of mild steel sharrp enough to shave hair but not for long

Dtraight high carbon steel that has been heat treated to have fine grain can get sharpest because of that fine grain. Hair topping sharp where it will trim hairs when held off the skin. But it will not hold that fine edge long.

The more acute the angle the better it will cut and the more delicate that edge is. If on the hard side it will chip, on the soft side it will roll. A less acute edge id harder to chip or roll but will not cut as well

Once you start adding more than the .85% carbon iron can absorb to make martensite the excess carbon will seek something be bond with and form carbides. Carbides are very hard and wear resistant and will help a steel hold its edge. Carbides are also larger than the grains of good steel and will not allow as fine an edge as the edge cn not be finer than the larger grain structure. D2 is an example of this. It has 1.5% carbon and .90% Vanadium and .8% Moly It forms Vanadium carbides which are very hard. It id used in punch press dies, metal shear blades, forming dies etc. A blade frame it will get rough shaving sharp and stay that way because the carbides are very wear resistant. It is also hard to sharpen because, HEY, it is wear resistant and that works both ways. M4 is similar only it has tungsten instead of vanadium and forms tungsten carbides, which are not only wear resistant but also heat resistant. Lathe cutters, metal saws etc. It makes one of the very best edge holding blades bar none. You will wear out several quality grinding belts getting that initial edge on it once it is hard. I have a stack of industrial hack saw blades of M4. About 1/16" thick. They make great fillet knives it you want to burn up $50 or so in grinder belts to make one and put the holes for scales in with a plasma cutter. Because of the carbides both of these steels are brittle because the carbide size in relation ship to the martensite grain

There is no free lunch in the steel world. Harder means more apt to chip or snap, more wear resistant means hold and edge longer and harder to sharpen.

A straight high carbon blade will get wicked sharp, a 5160 blade can be bent in a 90 degree arc and spring back, a D2 blade will chop a nail in half and the edge will be fine. You make the hard use chopper, survival knife or hatchet from 5160, you make the straight razor or chef knife from W2, 1095. I make my drop point hunter knifes from D2, they will gut and skin your deer, my deer then your elk then mine and still cut the date out of your tag, but if you pry with one it will SNAP.

There are some excellent steels on the market now that have some great properties when heat treated properly. This means a digitally controlled oven. It also means that you best not be forging then and enlarging their grain structure because it would be difficult to reset. Look here
Best Knife Steel Comparison - Steel Charts & Guide | Blade HQ

For me if they shave they’re sharp enough. Don’t usually strop my blades except for those with a convex edge. Though I have several sharpening platforms I primarily use the Spyderco Sharpmaker with medium rods for every day touch up and or maintenance.

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BCCI Life Member #2068

Thanks for the education on the qualities of steel.