Shock it, bend it, dig it, stainless vs carbon?

[thewap]

I know that the Stainless vs Carbon argument has been debated may times over before. Most Randall owners will usually state personal preference of one over the other, based on maintenance, esthetics, and sharpness. The previous post in this forum about the Model 15 that took a bullet , made me think about the old Stainless vs Carbon deal, all over again. The 15 shattered, and saved the soldier much more damage than he sustained. But the fact that it shattered, was what made me wonder..

I remember a conversation I had with Mr. Hugh Bartrug years ago at a knife show. He had made a bowie for his son who was then in the Seals. Of course the blade was damscus. I asked him why a damascus in combat? according to Hugh, a damascus blade will not break. Rather, under extreme force it will bend. If in the rare event of such a bend, the blade could be pounded back straight. Taliking to Ed Fowler once, he told me that it would be highly unlikely that one of his forged carbon blade would ever break. He too claimed that rather it would bend under extreme force.

The question of this post is: Stainless steel with it's higher content of chromium, would it not make a blade more succeptible to breaking because of brittleness, than carbon? , and would a Carbon Randall model 15, shatter under the same circumstances as the stainless that was hit with the bullet?

Even Mad Dog's knives, made of 01, claimed that a soldier carrying a short sword made by him, was hit with a bullet. But it did not shatter. The bullet loged itself in the blade. Most of you know that Mad Dog's 01 steel, held up in the Seals test above all others. Bo Randall's favorite was 01 as well. What do you guys think, and what is the technical argument?



The other question is, when chopping brush, it is inevitable that sometimes you might accidentally strike the ground with the knife. That can wreak havok on an edge. Would the stainless Randall hold up as well as the carbon?

[Moosehead]

You pose two good questions, Marc!

Unfortunately, my knowledge of these matters is insufficient to even hazard a guess. :confused:

I hope some folks with metallurgy backgrounds will weigh in here.

Moosehead

P.S. I do know that 10lbs of lead is equal to 10lbs of aluminium.

[thewap]

errrr...equal in weight Moose....not in size ...

[Seussbrother]

Hi Marc. Very interesting questions! I really hope some of our bladesmith friends will weigh in on this one. I think we are deep into a discussion of heat treating and tempering as well as steel selection. If the steel is high carbon and only hardened to say, the 40s on the Rockwell scale, it is very spring like and probably would indeed absorb a bullet shock with permanent deformation instead of fracture. If, on the other hand, it was hardened to RC 60+, I can certainly see it shattering. Having never dealt with forged steel, I would only guess that it would be tougher than non-forged and less brittle. Machining high carbon tool steel is very different from machining stainless steels in that by comparison, the stainless steels give you a sense of gumminess not seen with the regular high carbon steels. I would suspect that after heat treating, some of the malleability of the stainless would remain making it less apt to shatter at the same hardnesses. We old clowns who remember the earlier days of the stainless steel kitchen knives have the picture firmly etched in our heads of edges folding over and permament deformation of the edges of the blades when accidently knocked against a skillet or something equally unforgiving. Stainless steels have come a very long way since then. During the same time frame, a good carbon steel bladed kitchen knife would likely be more liable to chip when struck against something unyielding. One has to remember that at that time, people had been heat treating carbon steels for hundreds of years and had a much better understanding of it's qualities and how to achieve predictable results while stainless was really in it's infancy and the composition and heat treating of it were early in the discovery realm. Another facet to this discussion is grind angles which can either enhance the good or hide the poor qualities of a steel in a knife. This would also have a huge affect in the "blade in the ground" scenario.

Great topic! I really hope that our cutler friends will share their experiences and impressions!

Seussbrother

[thewap]

Hi Seuss, I agree that temper is paramount to the strength and performance of a blade and it's edge. And many knife makers have argued that proper tempering or selective tempering is key to "better steel" rather than forged vs stock removal. You bring a very good point about the old stainless kitchen knives and how they would bend. It is of interest to note though, that Mad Dog's blades I believe are tempered at 59, Bartrug's Damascus, give or take 57, Randalls? I think around the same. Damascus on the other hand is hard to compare in this argument, because of the lamination factor, I believe making it very unlikely that a Damascus knife (properly forged and tempered, mind you) would ever shatter. Since Randall forges to shape both stainless and carbon, that leaves out that argument. I guess we would have to narrow the question down to steel selection and chrome content ?. :confused:

[Co_Outdoorsman]

I know little of metallurgy and it's varied and complex recipe...

I do know wound ballistics... I would take a knife that could bend rather than shatter... force being force there would still be blunt trauma in either scenario... the kinetic energy being just that... energy passing through the blocking item to be transferred over a larger area IE the width and length of the blade... however with a shattering blade we now have multiple projectiles ergo shrapnel tossed into the mix, along with blunt force...

Then one would have to factor in trajectory and energy imparted to the interposing article... say the knife blade... A glancing hit would more than likely ricochet from most steels while a straight on impact with a malleable bullet tip (hollow point) would more than likely cause bending as the bullet begins rapid deformation upon impact... howsoever if we are talking military projectiles which are almost universally FMJ (full metal jacket) which is less likely to deform...

This is quite the proposed question and look forward to more in-depth answers than my prattle...

PS... I still like stainless over carbon... just cause I do...

PPS and 10 pounds of feathers is larger still in mass equals weight ratios...

[2Shot]

Scott,

I learn something everytime I read one of your posts. Be it EMS stuff, or what kind of metal I should carry. I too like stainless.

You know what I do, so it is important what I carry.

Pretty cool that most of the guys/ladies with brains came to this new site. Wahoo Moose!

Kent....the old..Blue7570

[RedElk]

Stainless vs. Carbon? My collection is 50/50 and I still can't decide.
I'll get back to you on it after I buy a few more.

[thewap]

The one thing that always puzzled me is the stainless that Randall chose, which is a 440B type of steel. It is generally agreed in knife steel analogies that the 400 series of steel are not well suited for making a knife. They have a reputation of poor edge retention and are not shock resistant. (which relates to the original question of these threads) the exeption being 440C if tempered correctly and freeze cooled. Even so, some 440C blades have broken when subjected to extreme tests. The puzzling aspect of Randall's choice of440B, is perpetuated by the fact that Randall forges it. And it seems successfully, as a decent edge can be achieved on stainless Randalls. But there is no information I could find on the shock resistance aspect of forged 440B Randalls, or the enhancement of 440B by forging. Is there a proprietary formula Randall uses?

On the other hand, Randall's original choice of tool steel Starret 01 Swedish is obvious . 01 is generally accepted as one of the best knife steel around. Incredible shock resistance, good edge holding and retention. My personal belief is that it outperforms most all other steels , including so called supersteels. An upgrade to 01 is difficult. Now 06 I understand is even stronger than 01, with the same excellent properties. But very difficult to work with, and even more difficult to acquire the stock.

This post is not meant as stainless bashing. Rather it is more of an attempt to understand Randall's choice of stainless and how do they make it work? Even in consideration that Randall may have a formula to enhance 440B to acceptable cutlery use, Back to the original question: would Randall's 01 have shattered by being struck by a bullet? , did it shatter because of the inherent properties of 440B , despite Randall's successful formula of forging?

Your thoughts and comments please!

PS Red Elk, perfect answer!

[jclarksnakes]

....Just to add a little smoke to obscure this discussion about the currently being used stainless steels versus 01 steel. My stainless 1977 Solingen 14 was used a lot. I never abused it but it cut lots of things during the many years I carried it. It was very sharp when I got it and I think I remember touching up the blade with ceramic sticks only a couple of times. It is still very sharp. I do not know what alloy stainless the Solingen blades are but it is good stuff.
Jeff

[Larrin]

Carbon steel is generally tougher than stainless, especially when it comes to steels like 3V and S7. According to Crucible steel, 3V (at 60 Rc) would take about 65 ft. lbs of force to break in a charpy c-notch test, while something like 440c take about 16 ft. lbs at 58 Rc. However, 3V is very tough, and 440C is one of the weaker stainlesses, O1 at 60 Rc would take about 30 ft. lbs, and A2 about 40 ft. lbs. Most simple carbon steels (1095, 52100, etc.) would be about the same as O1. The other advantage of carbon is that it can be differentially heat treated, for a soft back with a hard edge, making it so that it will bend before it ever breaks. Differentially heat treated stainless is generally seen as impossible, though there are a few that have claimed to have done it (i.e. Thomas Haslinger). For more comparisons, D2 takes 23 ft. lbs at 60 Rc, and S90V takes 19 ft. lbs at 58 Rc (typical hardness for S90V). 154-CM and S30V are hard to find good charpy tests on, it seems they would be somewhere around 17-20 ft. lbs.

In the end, toughness is overrated, and I believe a real using knife should have stainlessness.

[thewap]

Jeff,
My preference for carbon is a personal one...It is indisputable that Randall knives are quality, wether carbon or stainless. I understand there is a lot more to a knife than just the steel. Temper, grind, fit, finish, materials, design and steel have to work in unison, to make it an outstanding knife. Randalls are outstanding knives, wether carbon or stainless.
I know that the stainless Randalls cut well. I also know edge retention is good. But the 440B question is a question I have asked myself many times before, and never got a clear answer, as myself, and I'm guessing most people don't seem to have any info on the process and propriety of Randall forged 440B.
It would be also interesting to hear if Randall Solingen stainless steel differs from Randall USA stainless...

Larrin,
thank you for your informative post. According to your numbers, that would put stainless at 40-50% weaker in the shock dept. What that translates to I am not sure, as I have never been able to break a stainless Randall knife. I agree that shock resistance is overrated and that it has no real importance to most knife users. i also use regularely Tungsten type blade which can acheive and hold an incredible edge, but give it shock and the edges will chip, or under hard human force will snap. Nevertheless, I like the steel because of it's cutting ability in the real world. A2 is touted as "THE" shock steel, but I have also heard it is not very abrasion resistant, which doesn't make for excellence in edge retention. I guess some knifemakers make it work through proprietary heat treating. I also am guessing that the difference in most carbon steels excepting simple steels as W1 and W2, is not in shock, but more in edge retention. I have owned and used Stainlesses such as 154CM and ATS 34, and am not particularely fond of the steels. But thats just me. I actually like Randall stainless better. 440C by reputable knifemakers have done well for me. I use regularely a 440C bladed Funny Folder by the excellent artisan Ted Dowell, and also owned a blade by Jim Hammond, which was superlative in every dept.

While shock is not important for most knife users, there is still an argument to be made for psyche.
The reality for a soldier under fire is very different than my reality. Wether a carbon stainless would have deflected or imbedded a bullet strike, would make a psyche confidence difference to a soldier.
The post about the blade shattering under fire, also left the blade's shrapnel doing damage to the soldiers leg. I understand that many factors must be considered such as ballistics etc.,
but hat still leaves my question as to forged 440B.. and Jeff's reminder of Solingen vs Randall USA stainless?.

[hammerdownnow]

I think the main difference is factory vrs. handmade. In a factory setting where volume=profit, time is money. In the handmade setting, time is not really an issue functionality is. It takes time, thought and a human hand to coax a piece of steel into a blade. Careful thermal cycling, time ,temps hardening and tempering is essential.Handmade carbons outperform stainless more often because of it ability to be manipulated easier in a home shop setting. Many believe that a blade needs to have a differential heat treat for peak performance. That only makes sense, an edge that will hold and a tough back and tip.
A factory made carbon knife is just as likely to shatter from a bullet as a stainless blade. (how many kabars have you tipped?) 440B in the right hands could possibly make a pretty good knife, doubtful that it would deflect a bullet "and" hold an edge without a differential het treat tho.

[thewap]

Hi Hammer,

differential heat treating is a good argument. I hear you about Kabars although they are a good knife for the money, they probably have a basic temper. I also think they are drop forged 1095. A far cry from hammer forged 01 or 440B. I know that Sean McWilliams used to forged 440B very successfully. Your analogy is right on the money concerning factory vs custom. Randalls are not factory, rather shop made. They have kept the same knifemaking process Bo Randall originally used when he made knives. The waiting list is as long as some of the best custom knife makers. They are also hand forged like custom knives. I believe Randalls are also dif heat treated. A Randall failing is a real rarity. Only under extreme circumstances in which a custom would also fail. A bullet, is an extreme circumstance.

Is it possible that Solingen had their own heat treating formula, which differed than Randall USA? :confused: