custom paring knife : alvin johnson

[Kevin Wilkins]

This is worse with many of the high carbon steels, I have done salt water soak tests on ATS-34 vs 1095 for example and ATS-34 looks much worse with greater pitting.



Which steels specifically and how were they heat treated and to what angles were they sharpened? Do you really think his results apply to blades custom hardened to the protocols described in the above?

As for a warrenty against rust, it isn't like the high carbon stainless blades are immune to this either, I don't dip my slipjoints in oil either. In fact I stopped oiling my knives, carbon and stainless a long time ago.

-Cliff

Cliff I didn't write the book. You brought up the meat cutting thing; I pointed out a published report with much different results than those to which you alluded. If you have questions about Mr. Juranitch's book, you'll have to direct them to him.

I have never ever made a folder with a stainless blade which has developed a rust problem. But you are correct, stainless steel is not "immune" to corrosion problems. I don't know of anyone who has claimed it was. It is much, much more resistant to rusting than normal carbon steel, hence the moniker: stainless steel.

Brownshoe: How can I be any clearer? I have stated repeatedly in this thread that slip joint folders tolerate rust mechanically MUCH BETTER than liner locking folders. They still look rusty, but they open and close. What are you not understanding about this?

The original poster asked about a Sebenza which is a tactical, framelocking folder. I attempted to provide an answer to his question in my first post.

I use Damasteel powder metal damascus in my folders, which is very stainless. For information about this steel, contact www.damasteel.se.

Steelhead: As far as I know there is no way to make a folder with an insert as you suggest.

Some people have almost no problems with knives rusting and others do. As I have said above, folders give the most worry in the pivot area, which is why I am trying the TiAlN coating. This is much harder than the bronze bushing and washers and also also fairly slippery to help reduce the need for other lubrication. I am anxious to see how well it inhibits rust. If you want a folder with a carbon steel blade, check my website, I can certainly make you one. I don't know if I am allowed to give my URL, but if you google my name, you will find my site. I think M2 HSS makes a super cutting knife.

 

[Steelhed]

Kevin - I have a Benchmade AFCK with an M2 blade. I don't care for it much. Not because of the steel, but because the edge bevel is too thick for that type of blade. As far as I know M2 may be overkill when it comes to a non stainless steel. It has properties for high temperature use that a knife will never need. Even so, from what I hear it is a very good steel for knives. I don't see much difference between it and other non stainless steels at the same HRC. Granted, M2 is usually run at a higher HRC than other high carbons, but that does not mean the others can't be run higher as well. For me the jury is still out on M2.

As far as an insert goes. If I were a knifemaker (some day I hope) I would drill out the pivot hole and either wedge fit or sinter a stainless or other material plug into it. This would be center drilled for the pivot pin. That way you could have a corrosion resistant material to hold the tolerances while enjoying the benefits of high carbon steel for the edge. I understand your concerns about liner locks, but since I like them the least of all the available locks systems out there that would not be a concern of mine. Frame locks might be a problem, but again inserts or sleeves could solve this problem.

 

[Kevin Wilkins]

Steelhead, I also have a Benchmade AFCK in M2! I like the blade OK but I understand your point about its not being thinner ground. I find the construction of the knife somewhat flimsey. It's of the screw down the pivot until it bind then back off a tad construction. No bushing is used and the washers are Nylatron.

I like the fine grain of the M2 and its ability to take a great edge. This is also true for other carbon toolsteels. I also use 52100, O1, O2, D2 and A2, all of which have their good points.

I doubt your insert idea is workable and if start making folders, I bet you'll see why! Sintering steel isn't too easy for heat treated parts. I already use a sintered bronze bushing in my folders and a heat treated, lapped custom pivot.

I have some ZDP-189 laminated steel from Japan which I will be testing. The outside layers are ATS-34 but the cutting edge core element is a High Speed Monster Steel ! :thumbup: I think a laminated steel offers more potential in that direction than composited blades which would be a technical nightmare.

I do really like carbon steel for fixed blades. I have begun making integral knifes from 52100, O1 and O2 which are selectively heat treated herre in Germany by Markus Balbach. He is one of Germany's most experienced smiths and forgers. He makes the Damascus for Böker. I do the design, machine programming, milling and grinding in my shop.

It's not that I don't think carbon steel makes a fantastic knife. I do. Properly done stainless blades are also very good. There's always a trade off somewhere dictated by usage, customer wishes, etc etc.

Maybe if some of you guys all start mailing Chris Reeve, he'll do a run of Sebenza's with carbon steel blades? Perhaps if a dealer agreed to take an entire small run?

 

[Cliff Stamp]

Cliff I didn't write the book. You brought up the meat cutting thing; I pointed out a published report with much different results than those to which you alluded.

It doesn't contradict anything because it is so vague it is completely meaningless. Alvin compared 1095 heat treated as described in the above, M2 from power hacksaw blades (not rehardened, left as is) and ATS-34 heat treated by Paul Bos. The edge profiles were similar as noted to the above paring knife to maximize the cutting ability. There are lots of myths about steels based on comparisons which are highly skewed, the above by JJ is one of them and is so off that it is farcial.

Steelhed, M2 is one of the finest steels for knives which are designed to cut well and stay sharp long. Benchmade leaves it far softer than optimal for this purpose but the hardness they run does leave it at the peak for toughness so it could be argued for a more "tactical" or hard use knife. In a utility knife it should be hardened to the maximum secondary hardness peak of about 65 HRC. You need to get it optimized edge wise to appreciate it, leaving it thick is a waste, if that is the grind you need, then that is the wrong steel.

-Cliff

 

[Kevin Wilkins]

Vague? Meaningless? Did you read another book perhaps? Or did you read it at all?

The results are not presented as the end result of a scientific test for final determination blah blah. They are anecdotal results of a blind test conducted with identical knives, excepting the blade steel types were in one set of knives stainles and the other carbon. Juranitch was in the business of professionally sharpening knives for the meat industry and sharpened all the knives himself in the same way. The meat cutters didn't know which type of knife they received each morning. Juranitch says he was also very surprised that the stainless knives stayed sharper longer.

It seems anything not cooked up by your friend Alvin is of little interest to you. I hope some other readers will check out Juranitch' book. As I said earlier, it's an interesting book.

 

[Steelhed]

Kevin - You may be correct about the insert idea. You and Cliff seem to like M2 alot. I will have to look around to see about finding a fixed blade in M2 to give it another look.

I too like fixed blade knives in all the steels you mentioned. I think my personal favorite right now is hand forged, differentially heat treated 5160 or 52100, as long as the HRC along the edge is at least near 60. I recently obtained a nice forged Nessmuk type knife made out of L6 and it really takes a nice edge and keeps it.

Don't get me wrong, I like stainless steels too. I have a Spyderco Calypso with ZDP-189 and that knife is about the sharpest thing I ever pulled out of a manufacturers box. It cuts cardboard better than anything else I have, and after quite a bit of cutting I still have no need to sharpen it. So I am interested in these new laminated steels. The next step will be to find a good fixed blade with laminated stainless, maybe a Fallkniven or something else with ZDP-189.

BTW, I visited your site. Nice knives from what I can see. I especially like the Ghost Dog and F7.

 

[Cliff Stamp]

They are anecdotal results of a blind test conducted with identical knives, excepting the blade steel types were in one set of knives stainles and the other carbon.

And again, which carbon steels, which stainless steels, under which heat treatment protocols and sharpened to what angles. Yes it is vague and meaningless unless this is specified. I was not stating the whole book is vague and meaningless, just that specific claim.

Consider someone here posting a review of two knives here one in stainless and one not. He doesn't specify what the steels are, how they are hardened, or how they are sharpened. He then uses the results to argue for stainless over carbon *in general*. You really think that is a sensible arguement?

Or just think in general of comparing something like that, how about one forged knife vs one stock removal without saying who made the knives and then using the results to judge forging vs stock removal. You think that is a valid arguement?

And is isn't because of something "my friend alvin" said, as noted it is based on ASM data, and I have personally done the comparisons to confirm what Mike found when he checked Alvin's claims over a dozen years ago.

Many others have done the same since then, Chas Clements for one has used one of Alvin's blades and found the same thing, you won't get a fraction of the performance in stainless.

Alvin also doesn't sell his knives, and tells others exactly how he makes them including the heat treatment, and even gives away kit knives to those interested. He has no agenda outside of wanting to make a better knife and help others do the same.

-Cliff

 

[thombrogan]

Mr. Wilkins,

I'd also like to point out that Juranitch's study isn't necessarily applicable to all low-chromium blade steels. Unless specified, 'high-carbon' steels used for kitchen cutlery tend to be 1070 or 1095.

When cutting corrosive materials (in my case, staghorn sumac trees), I noticed that 52100 and S7 would tarnish almost instantly, but M2 wouldn't. The tarnishable steels resisted tarnish when sharpened to a high polish, but nowhere near as well as the M2.

Also, we, as knifeknuts, constitute so small a percentage of the steel bought from manufacturers such as Crucible, Bohler-Uddeholm, or Timken-Latrobe that even if we stopped buying steels made from S30V, N690, or 14-4CrMo, they'd barely notice.

 

[Steelhed]

What! You mean we knifeknuts don't rule the roost when comes to steel manufacturing? Well that only means we need to buy more knives until we control the market. I will start immediately.

 

[Redguy]

1095 or CV are the only steels to make a knife blade from.

Wow. So it's time to all Bladeforums member to trash our VG-10, ZDP-189, M2, BG-42, D2, INFI, S30V, 154CM, SR101 and 5160 blades? You are wise, constructive, and there's no way can be confused with a broken record.

edited for spelling

 

[Kevin Wilkins]

Folks, Mr. Juranitsch never claims his informal test applies to ALL stainless and ALL carbon steel knives. Neither do I. He also never claims it was a "scientific" test to be the all proving test and end all discussion. Neither do I. He says what he did and what came out of it, and he is a person who sharpened knives as a profession for many years, so I think he may have some knowledge of the subject.

Somehow I don't see where the "science" comes from for this guy Alvin's test using knives made from old saw blades. I don't see his results as being an more valuable than Juranitch'. Both provide anecdotal evidence and both are certainly interesting. I don't understad why Ciff wants to go to such lengths to discredit Juranitch and promote Alvin (!) as the author of a new Gospel on the subject. and actually it's getting all a bit boring.

But hey, not to go out on a negative note: Cliff seeing your review above, you've cut up enough goodies to make a pretty good Indian Curry there. Mix yourself up a nice spice mixture and invite Alvin over for a fry! :thumbup:

 

[Cliff Stamp]

Somehow I don't see where the "science" comes from for this guy Alvin's test using knives made from old saw blades. I don't see his results as being an more valuable than Juranitch'.

One gives you the specific steels, the way they were heat treated, and the exact way they were ground and how the edge retention was tested and is based on ASM materials data and has the results independently verified by several people over a period of about 20 years, the other does none of that. They are not at all similar.

I don't understad why Ciff wants to go to such lengths to discredit Juranitch ...

I am not discrediting him in general, but a method of evaluation. I would say the same thing if anyone tried to use a similar method to make a point.

As for "old saw blades", that is cute, so I guess all the forgers who don't use precision ground bar stock can be similarly dismissed. Alvin does by the way use bar stock for 1095 and O1 knives.

The M2 comes from saw blades, why anyone would look upon this as a negative is odd, considering how powerhacksaw blades can cut.

I'd also like to point out that Juranitch's study isn't necessarily applicable to all low-chromium blade steels. Unless specified, 'high-carbon' steels used for kitchen cutlery tend to be 1070 or 1095.

It isn't the steel that is the largest issue, but the heat treatment. I have a bunch of old Case carbon steel kitchen knives, they are *really* soft, ~45 HRC, you can file them easily similar to a machete. They would not hold an edge well compared to 440C class stainless at 55+ HRC at the angles JJ uses which is 20 degrees for a microbevel. It doesn't surprise me what JJ found.

If you brought the edges down lower it would be interesting because the stainless would crack apart, however the carbon steel is so weak at that hardness it would ripple readily so it would be a poor vs poor comparison, neither would do well but the stainless would lose its main advantage. Of course ramp the carbon steel blade up by 20 HRC points and the results are more than a little different.

Not to mention I doubt JJ used any M2 blades, which you would not call "carbon steel" anyway, or any of the tool steel blades which are very hard, Japanese style for example.

-Cliff

 

[kevtan]

Cliff, I adore M2 from old hpowered hacksaw blades and so does my mom!! But I have noticed that the used hacksaw blades do sometimes have different hardness levels on different parts of the blade. Cud you do an analysis of used hacksaw blades to see if this is true? Most particularly the hole end parts wud be full hard but the part most used where the start of the cutting stroke is, wud be softer by quite alot as tested using a benchgrinder.

 

[Cliff Stamp]

Alvin did exactly this recently, the hardness was ~65 HRC and uniform. The teeth of course could get drawn from running too hot, though they are HSS they can suffer temper draws it just takes a *lot* to get them to that point.

-Cliff

 

[me2]

Cliff, IIRC, you sharpen this paring knife and the O1 knife on a stone finer than a 4000x water stone. Can you comment on the performance of these type blades w/ a course finish, like 100x, similar to the tests on the BK-7?

 

[Cliff Stamp]

Awhile back on rec.knives the idea was proposed that coarse grits are "crutches" for knives with a low inherent cutting ability due to a thick profile. I think this is worth discussing, but not true in general, especially for knives that are multi-purpose and move beyond pure cutting.

However for those that are so optomized coarse grits are rarely needed. The cutting ability of these knives, slicing on ropes and carpets is very high with a high polish. Joe commented similar in regards to the Calypso Jr. as a high polish rope cutter due to the very thin profile.

I have run very coarse edges on hard steels before, I ran Mel Sorg's blade in D2 at 62 HRC ~5 degrees per side left with a 100 grit AO belt finish, it made an exceptional hemp rope cutter, both in terms of the minimal force required and the exceptional edge retention.

For completeness I should run some coarse cutting trials with the above knives, the problem is though they are *so* thin that the effect of the coarse grits is highly magnified. For example on the O1 blade, at ~0.04" back from the edge, the blade is 0.005" thick.

This means that the teeth left are much greater than would be on a blade with a heavier angle, it is basically inversely proportional. So the teeth on a 2 degree edge are 10 times as large as those on a 20 degree edge, which is why the knife seems much more aggressive even with a high polish.

-Cliff