Question Regarding Round Knife

[gtwister09]

I can personally attest to the heat treatment or the lack thereof in ATS-34. I received a set of 3 knives from a major maker as a gift/trade several years ago. Two of the knives (both the head and half round knives) would only last 10-12 inches of cutting before I could start to feel a marked decrease in ability to cut. At first I thought that I had screwed up in sharpening but quickly ruled that out when comparing it to my other knifes as well as the third knife. In comparison, the other knife from this maker could last 10-20 times longer easily before sharpening. The Rose's and others lasted even longer.

I had the benefit of doing some major testing with cutting tools, materials and process for a defense contractor 15+ years ago with cryogenics and heat treat so I figured it was a lack of heat treat. Since then I have talked with the maker and we tried another one w/o heat treat and shazam my thoughts were confirmed. We could only cut 10-12 inches and feel the decreased ability to cut. Heat treated to 59-60 RC hardness and it lasted many times longer. As Terry said a nice shiny tool that wasn't much good as a tool until heat treated properly.

Regards,

Ben

[Art]

I am going to take a little different tack here and say, Buy your head knife, or any knife for that matter by the maker. I have made knives for a while (since the '80s) with my highest production in the '90s, maybe several hundred or so. In my experience, most really good makers know their steel quite intimately, and don't experiment with a lot of other steels. It takes time and a few mistakes to learn how to work and treat any steel and a whole bunch of different product just confuses matters. My favorite mill was Latrobe. Latrobe made bearing steel for Timken who owns them now. I was also a made in the USA freak so Latrobe and Crucible were my pets. Needless to say, most of my blades were made of 52100 or BG-42, both great steels if properly worked and heat treated. Of course 1095 and O-1 are steels that every good knifemaker learned their metallurgy heat treating. Crucible was the high tech mill of the steel world, they made, and are still making some steel with incredible technology, their particle metallurgy makes some really high tech and high performance steels that are good for knifemaking.

But I digress. What I am saying is it's all about the maker. You need to have used, or trust someone that has used a maker's knife to give you a recommendation. If a maker makes a not so good knife, don't expect to hear it on any forum, it just won't happen. If you want the real skinny on a knife, your going to have to get it eyeball to eyeball.

As far as edge profile, I prefer a teardrop profile. I like to leave more metal behind the edge than you get with a hollow ground profile. The disadvantage is that the teardrop (Moran, Appleseed, etc) will require some reprofile work sooner than a hollowgrind, but can still be resharpened in the field without too much effort, well at least until the thing becomes a cold chisel. I like steel behind the edge, if I wanted a thin knife, I would have ground a thin knife in the first place. But Art, how can you like Bill Buchman's knives, they are thin? Bill's knives are thin, and they were made to be thin, they were not made to be camp knives, but they work, damned well if I do say so. Nevertheless, thin knives have their problems too, you can snap off a tip in a heartbeat if you aren't careful. Another thing about edges, 15 degrees, use a matchbook to learn it and use it for your head knife, less than 15 and you are getting into fragile edge territory where it will last about 2 feet or less. You could use 18 or 20 degrees too, find what's best for you.

Last but not least, learn how to sharpen, read about it, get some old knives and practice, once the mystique is gone, it is just another skill in your toolkit, hell, you can (and I have) make reasonable money going from kitchen to kitchen sharpening knives. Food service folks don't have a clue about how to sharpen cutlery, and now they use steels that actually take metal off, so you will always have work. A 10 power loupe and a dry erase marker are necessary if you really want to learn to sharpen. I have heard some folks say that you only need to strop a head knife once it has been properly sharpened. Sorry, It ain't true folks, eventually the edge will round and no amount of stropping will set the edge back, a cork belt with compound will, and stones or abrasive belts will, but just loading a strop with green rouge is not going to do it, you have to learn to sharpen.

So to reiterate:

Rose

Gomph (Albany N.Y.)

C.S.Osborne (Newark)

The above are quality knives all of carbon steel, it is possible for them to be mishandled while sharpening which will cause soft spots, an experienced sharpener or knifemaker can grind these out, it takes some work and should be left to those who can. You can get lucky on eBay and sometimes not, you can buy from Bob Douglas or Bruce Johnson and get a good knife.

Bill Buchman

Bob Dozier

Dewey Peters

Gomph (Ellis Barns/Lonnie Height but I don't know who the real maker is)

Leather Wranglers (Paul Zalesack)

These are stainless steel knives, there are other makers, but I don't have knives by any of them yet so I can't give them a shout. The above are excellent cutting, quality knives.

Art

[hidepounder]

This has turned out to be an amazing thread thanks to the explanations by you pros. Thanks! But would you talk about edge geometry just a little? Without some of the more sophisticated equipment, sharpening a head knife can be a pretty difficult task. And if you are not sure what to look for you may never be able to achieve a really sharp edge. The equipment that I have really isn't very friendly for sharpening unless you have a much higher skill level and a lot more knowledge than I do. Consequently I sharpen by hand and that can be time consuming and frustrating. I use a variety of diamond stones and super fine sanding paper and I strop on a paper wheel (which is probably not good) and finally buff with green rouge. I'm hoping you guys will help me improve my techniques so that I am more efficient and successful.

I had a horrible time trying to keep my first head knife sharp. It was slways hit and miss....sometimes I would get it right and other times I could not and it never cut like it does now. I was not inept...I had pretty decent knife sharpening skills, except for the head knife. It wasn't until I met Bob Douglas that I learned that what I was trying to sharpen was never going to be sharp without being tuned up first. What Bob taught me was to better understand what the final 3/4" of that knife edge should look and feel like (edge geometry). He explained that most head knives straight out of the box had too much "shoulder" and had to thinned in order to achieve the optimal edge geometry. He showed me the difference in the look and feel of a knife that is tapered all the way down to the cutting edge as opposed to a knife with a constant thickness which is then tapered to the cutting edge. What a huge difference that little tune up made in the performance of my knives!!! This is not something that I could ever explain....it's something you have to see and maybe more importantly "feel" repeatedly until you are able to recognize the correct geometry. Terry and some of the other pros can translate all of this into angles and material thickness, etc. My point in all of this is that there really is quite a lot to learn about using a head knife and more importantly, maintaining one. One shouldn't be discouraged about getting started with one, but should begin the learning curve as soon as possible because life gets much better after you are able to use and maintain this fantastic tool!

Bobby

Edited June 19, 2011 by hidepounder

[gtwister09]

Amen to what Art said about sintering technology, Moran profile, confidence in the maker and so forth. The maker has to do their homework and have accuracy and repeatability. The only knives that I haven't tested or have are Paul's and Terry's. There is TONS of engineering information and comparisons to determine the ideal material for you. As Art stated you are depending upon the maker to know his/her material "intimately" to make the best decision in design that will yield the best knife for a particular purpose. However in order to do that we have to educate ourselves or depend upon others to guide us in our decision.

Sharpening cheap kitchen knifes is a great way to learn the skill of sharpening on a slack belt system. As I said earlier, after the initial profile it is relatively quick to resharpen and polish your knives. As with anything the time practicing is well worth it. Art gave an excellent tip with the marker and magnification because then you can explicitly see what is going on with the edge.

Regards,

Ben

[hidepounder]

Art, I must have been typing when you posted. I think you are spot on about choosing makers. I know I do that.... I think a lot of us do. It's not critical to understand everything about the characteristics of steel....especially when I can purchase from a maker that I have confidence in. Your example of using a matchbook to get an idea of what 15 degrees is, and that 15 degrees is a good angle to shoot for is exactly what I wanted someone to tell us. I'd like to know more about what you all use to sharpen with too. And just what is a cork belt? Is that something that we should have?

Bobby

[hidepounder]

Sharpening cheap kitchen knifes is a great way to learn the skill of sharpening on a slack belt system.

Regards,

Ben

Ben....what speed and what grit are you using with a slack belt? And how much deflection in the belt is most desirable?

[gtwister09]

Bob,

Ideally you want something slow but you can compensate for the "fixed" speed when you use a 1X30 belt sander (which is a WHOLE lot cheaper than a KMG or clone - these allow slower speeds). The grit also depends upon how much material you need to remove or if the edge of the blade needs to be reprofiled. After the initial profile with the slack belt you don't have to progress through all the grits before you polish it with the rogue and leather belt. Likewise there are individuals who use a mousepad or doubled Scotchbrite pads to aid them in hand sharpening a Moran edge.

The cork belt is another belt than can be used to sharpen with and loaded with compounds (your choice).

I have sent you something offline.

Regards,

Ben

[Knipper]

test

Edited June 20, 2011 by Knipper

[Knipper]

I happened to think about what has been said about the edge angles on head knives for resharpening. Its important to remember that when you hone one side to a 15 degree angle and then turn it over and hone the other side to a 15 degree angle, you are getting a combined angle on the edge of 30 degrees. Many know this, I'm sure, but without bringing it up, some may think that setting your blade at 15 degrees for both sides will yield 15 degrees at the edge too. If you want an included angle of say 20 degrees, then you have to hone both sides at 10 degrees, measured from the edge to the back of the blade on each side, of course....

Also, assuming we are talking about a convex (Moran) edge here, I was thinking that it would really be hard to measure an actual angle on a tapered convex edge, as the rounded taper itself thwarts any effort to do so accurately...at least with my measuring devices.

The main body of the blade and its taper towards the edge, gets to be a pretty small angle when you think about it. Assuming you start with a thickness of 1/16 inch, and then taper it toward the edge over a length of say, 2 1/2 to 3 inches, that initial taper (not the tapered, rounded angle of the actual edge...!) will probably be only 3 to 5 degrees...maybe even less. I think how its sharpened after that (from the edge back to 3/8" to 1/2" into the blade) is what will make the difference in how well a blade cuts. Just my opinion !

Edited June 20, 2011 by Knipper

[Art]

Hi Bobby,

15 Degrees is a good angle to shoot for and 22 is ok for utility type knives like some hunting knives. When I say 15 degrees, I mean 15 degrees on each side of the edge, that's thirty degrees, but if I said that then someone would mistake it for 30 degrees on a side, which is good for an ax not a head knife. A matchbook is a more understandable wedge to indicate the angle of a side, and you can put it down on a stone and visualize it. Darned hard to find a matchbook anymore with all the anti-smoking laws, but they are out there.

The cork belt is something used by knifemakers and at one time was only made in 2x72 belts. Now with the little small sanders they seem to make belts in every configuration. So a warning about the cork belt. To the novice, a cork belt looks like it would make a really good strop, and it will if you don't put anything on it, the minute you put anything on it, it becomes an abrasive belt and will remove metal. Just so everyone knows.

With a cork or leather belt, take it off the machine when not using it, they wear out just sitting under tension

Also, you gents with these small narrow belt sanders, don't hang around too long in one spot, the narrow belt will cut a groove faster than a wide belt, practice with your sander/grinder before you put good metal on it. For practice, there are always crap knives in the kitchen, but you can also pick up shoe knives at auctions by the boxful for next to nothing, they usually are by United and have green handles, these are a few bucks new to give you an idea of the value.

Last but not least, you can ruin a lot of steel with power tools, but you still basically need to have stones for some things and if you buy four large (as you can afford) stones, soft, medium to hard, hard, and maybe ceramic or clay, you can sharpen almost anything.

Art

Art, I must have been typing when you posted. I think you are spot on about choosing makers. I know I do that.... I think a lot of us do. It's not critical to understand everything about the characteristics of steel....especially when I can purchase from a maker that I have confidence in. Your example of using a matchbook to get an idea of what 15 degrees is, and that 15 degrees is a good angle to shoot for is exactly what I wanted someone to tell us. I'd like to know more about what you all use to sharpen with too. And just what is a cork belt? Is that something that we should have?

Bobby