2 Myths About Carbon Steel

[hardheart]

Well, if you ever need to know how many 10's of a millimeter your knife will cut a branch,
I guess you can count on those studies! Good luck repeating those "conditons" out in the wild! LOL

Yeah, I can. You cannot. You have absolutely no idea how much one steel will out cut another. You could say how much one knife does compared to another, on a particular day, with particular wood. Is the humidity the same? Is the wood composition the same? Are the handle ergonomics the same? Did you have coffee one day and not the next? Were the knives the same sharpness? Were you cutting at the beginning of the work day or at the end? Did you cut using the same length of stroke? Were you cutting at the same height?

You are the knowitall without the core sample this time. Using a knife is not using the steel. It is using the handle ergonomics, the heat treat, the grind, the sharpness. It is using your muscles, your body position, your nervous system from one day to the next. It is not me using my knives, or any other person using theirs.

You know what I got from my lab testing? The exact same knife, tested twice in the same day, cut nearly twice as much material by only changing the sharpening angle. Two different blades, with the same alloy content, from the same supplier, heat treated at the same company, ground by the same person on the same equipment, sharpened by the same person, tested in the same place, had a 1000% percent difference in performance. Others test had a 4% difference. I know the exact differences, I know the exact variables changed. You cannot name any of that. That means for the large differences, you do not know the reasons. For the small differences, you cannot tell in the first place. You would provide an impact on the livelihoods of those in the cutlery industry by making a decision without all the information. You would tell someone to stop because based on your experience you know what carbon steels do compared to stainless steels without getting into the field of exact differences in hardness, geometry, test conditions, etc. Now it is you who do not know what is under the surface and would like to sit from a lofty position and spew knowledge.

Is the CATRA supposed to test for sparking against various materials? Is it supposed to test a hand tool at 300 degrees or ten atmospheres of pressure? I worked with tools and measuring devices deployed in oilwells over five miles deep under 8000 feet of water. My knife still just had to cut rope, cardboard, and tape at sea level in temperature ranges handled by my regular clothing. CATRA measures edge wear from slicing abrasive material. If you want a result from doing something else, then perform another test. But if you want to know how much stuff a knife will cut by slicing, then CATRA will do just fine.

 

[SR69]

Yeah, I can. You cannot. You have absolutely no idea how much one steel will out cut another. You could say how much one knife does compared to another, on a particular day, with particular wood. Is the humidity the same? Is the wood composition the same? Are the handle ergonomics the same? Did you have coffee one day and not the next? Were the knives the same sharpness? Were you cutting at the beginning of the work day or at the end? Did you cut using the same length of stroke? Were you cutting at the same height?

You are the knowitall without the core sample this time. Using a knife is not using the steel. It is using the handle ergonomics, the heat treat, the grind, the sharpness. It is using your muscles, your body position, your nervous system from one day to the next. It is not me using my knives, or any other person using theirs.

You know what I got from my lab testing? The exact same knife, tested twice in the same day, cut nearly twice as much material by only changing the sharpening angle. Two different blades, with the same alloy content, from the same supplier, heat treated at the same company, ground by the same person on the same equipment, sharpened by the same person, tested in the same place, had a 1000% percent difference in performance. Others test had a 4% difference. I know the exact differences, I know the exact variables changed. You cannot name any of that. That means for the large differences, you do not know the reasons. For the small differences, you cannot tell in the first place. You would provide an impact on the livelihoods of those in the cutlery industry by making a decision without all the information. You would tell someone to stop because based on your experience you know what carbon steels do compared to stainless steels without getting into the field of exact differences in hardness, geometry, test conditions, etc. Now it is you who do not know what is under the surface and would like to sit from a lofty position and spew knowledge.

Is the CATRA supposed to test for sparking against various materials? Is it supposed to test a hand tool at 300 degrees or ten atmospheres of pressure? I worked with tools and measuring devices deployed in oilwells over five miles deep under 8000 feet of water. My knife still just had to cut rope, cardboard, and tape at sea level in temperature ranges handled by my regular clothing. CATRA measures edge wear from slicing abrasive material. If you want a result from doing something else, then perform another test. But if you want to know how much stuff a knife will cut by slicing, then CATRA will do just fine.

Are you an Engineer?

 

[hardheart]

No, when working offshore I was an operator. I maintained the tool interconnects, the 5K psi air compressors, the 13KW generators, the air gun arrays, assembled the tool strings on site, deployed 2 ton air gun arrays in choppy gulf waters dangling from cherry picker lines after staying up 30 hours. When I was a kid I worked with my dad doing cutting/welding, running a backhoe, rebuilding engines, a little sandblasting and painting, etc. I don't wear a lab coat and I know what the field is like. Recognizing that material properties can only be measured when the materials are at the same condition doesn't require a pocket protector.

 

[SR69]

No...

Okay.

 

[me2]

So far you've only posted about the designers that caused trouble. It seems a little contemptuous. We do seem to agree that you need both, but it took two pages for that to come out when I said it responding to your first post. The type of engineer you describe is the one that irritates me to no end, though they seem to be getting rarer, thankfully. So, that said, where are the examples of the foremen that don't know the difference between high strength bolts and regular, or welders that try to weld 4xx stainless with carbon steel rods, or inventory workers who stack Ti parts and 3xx stainless parts next ot each other and forget to label them, or any of the other stuff people in the "real world" do that have plenty of experience but still don't know any better?

 

[SR69]

So far you've only posted about the designers that caused trouble. It seems a little contemptuous. We do seem to agree that you need both, but it took two pages for that to come out when I said it responding to your first post. The type of engineer you describe is the one that irritates me to no end, though they seem to be getting rarer, thankfully. So, that said, where are the examples of the foremen that don't know the difference between high strength bolts and regular, or welders that try to weld 4xx stainless with carbon steel rods, or inventory workers who stack Ti parts and 3xx stainless parts next ot each other and forget to label them, or any of the other stuff people in the "real world" do that have plenty of experience but still don't know any better?

Exactly. I only posted about the irresponsible engineers/designers.

The foremen on my jobs that would think they could get by with using inferior out of spec material on my jobs got booted.
I'm a stickler for adhering to specs. I never deviate (unless the client/architect would change the spec and then of course,
I had to have a directive in writing). I was hated by the cheaters and appreciated by the guys who wanted to do the right
thing, but I digress; I'm sure no one wants to talk about me (except maybe flamers).



(BTW, most of the engineers I dealt with loved me because I stuck to their specs and if I found an issue or potential problem,
I'd ring them up and talk to them off the record so that we could address it between us. We worked "together". And if they saw
something on an inspection, they'd bring it to my attention directly first knowing I'd be harder on the guys than anybody above me.
Again, no gods anywhere...all mortals. And those that did think they were gods and were wrong got humbled quick...I'd set them up.
And those foremen who thought they were smarter than the inspectors found themselves home watching The Maury Povich show at
2 in the afternoon the next day and picking up their kids from school while his crew worked with another forman.)

 

[me2]

Again, it seems we agree, it just took two pages to discover. It must be nice to have the influence necessary to get rid of someone who refuses to do what they signed up to do. On a wider scale than your jobs, the "real world" is sometimes closer to fantasy and dumb luck than anyone wants to believe.

 

[SR69]

Again, it seems we agree, it just took two pages to discover. It must be nice to have the influence necessary to get rid of someone who refuses to do what they signed up to do. On a wider scale than your jobs, the "real world" is sometimes closer to fantasy and dumb luck than anyone wants to believe.

I agree. Forums are not conducive to getting points out clearly quickly. :thumbup:

It only took me about 25 years to get to that point.

I never liked having to get rid of people, but every man writes their own career path with me.
Plus, if someone that was slacking was cut, the decision to do the right thing from then on
became contagious throughout the rest of the crew. But, I'd still be upset because I'd give
guys a few chances. No one's perfect, but when someone is going to hurt a job and won't
accept correction, then I have to put the workers who do want to do the right thing first.

 

[sodak]

I made no false dichotomy.

You certainly did. In my last career, I certainly was a professional engineer, and on more than one occasion, had to stop f@#$ing idiots who were:

A. too lazy or
B. too stupid to read

from incinerating themselves. When the specs and technical updates clearly caution and warn against certain procedures, and f@#$ing morons are so contemptuous that they won't heed the warnings, they can get themselves in a bind real fast. But hey, I was the new guy (2nd LT, so what did I know?), and nobody would listen, so I let the supervisor take flight across a loading dock thanks to 417 volts precise power. Then I got their attention. You'd be surprised how far the human body can propel itself under high voltage.

They started listening after that.

 

[me2]

From what I hear, having never been in the military, LT's have it pretty rough. Some people just have to pee on the electric fence to learn.

 

[Ankerson]

You certainly did. In my last career, I certainly was a professional engineer, and on more than one occasion, had to stop f@#$ing idiots who were:

A. too lazy or
B. too stupid to read

from incinerating themselves. When the specs and technical updates clearly caution and warn against certain procedures, and f@#$ing morons are so contemptuous that they won't heed the warnings, they can get themselves in a bind real fast. But hey, I was the new guy (2nd LT, so what did I know?), and nobody would listen, so I let the supervisor take flight across a loading dock thanks to 417 volts precise power. Then I got their attention. You'd be surprised how far the human body can propel itself under high voltage.

They started listening after that.

Kinda like the Don't push the big red button thing.

 

[hardheart]

From what I hear, having never been in the military, LT's have it pretty rough. Some people just have to pee on the electric fence to learn.

the ROTC and ring knockers tend to deserve it when they have an air of superiority at 22, but it sucks for the ones who are prior service. Still, an NCO trying to school a butter bar who happened to be a 1SG or warrant (my BOLC class had an admin guy who was an E-7, who then went WO1, and then went with the commission to 2LT) before commissioning is good times.

 

[sodak]

From what I hear, having never been in the military, LT's have it pretty rough. Some people just have to pee on the electric fence to learn.

Sometimes, although there are ways to give as good as you get...

Kinda like the Don't push the big red button thing.

Yup! They knew I wasn't joking when I told them the next one wouldn't get CPR again from me.

the ROTC and ring knockers tend to deserve it when they have an air of superiority at 22....

Pretty big generalization there.

Soryy for the thread drift me2, I'll get back on topic...

 

[SR69]

I certainly was a professional engineer...

Ohhh...I got it now.

 

[Lagrangian]

I would say, we only have a "complete understanding" of something when the theory, the lab experiments, and real-world experience all are brought to bear on the problem, and they all are in agreement.

Sincerely,
--Lagrangian

P.S. Off-topic, but maybe amusing:
Story about "pushing the big red button": In the book _The Design of Everyday Things_, Donald Norman tells the following story:
http://www.amazon.com/Design-Everyd...=sr_1_1?s=books&ie=UTF8&qid=1336368164&sr=1-1
A factory building was converted into a university-college. One day, during lecture, the professor could not figure out how to lower the projection screen (for showing a movie, etc.). All he could find was a giant red button, but taped to the button was a note saying,"Do NOT press this button." Since he couldn't find anything else, he thought,"Oh well. Maybe the red button lowers the screen, and it is just a warning about accidentally lowering the screen." So... he pushes the button. And nothing happens. Then 5 minutes later, an extremely irate man storms into the class and yells,"It says, do NOT push the red button!!" It turns out that the red button is emergency power-off for a separate wing of the building. A carry-over from when it was a factory building. The moral of the story: If you tell a user not to do X, that is not enough. You have to tell him _why_ he shouldn't do X, especially if the consequences are not clear. Norman's famous book is about designing user interfaces and consumer products; a _surprisingly_ difficult thing to do well.

P.P.S. Also off-topic: About the "rivalry" between theoretical physicists and experimental physicists:
My undergrad teacher, Prof. Sethna at Cornell, and one of my grad professors in solid-state physics at U.C. Berkeley, both said the same thing: Physicists know that the really important discoveries are made by the experimentalists. After discovery by experiment, it is only then that the theory guys go in and figure out how to understand it. Both are important. What good is observing something, if you cannot sufficiently understand it to make new science and/or create new technology?

The reverse does happen, but is rather rare. The standard example is Einstein who made almost imposible-to-believe discoveries in theory, which were later confirmed by experiment. There are other examples, of course, but they are relatively uncommon.

Instead the typical story is more similar to that of giant-magneto-resistance (GMR): Some experimentalists found that some materials under go extremely large changes in electrical resistance when placed in a magnetic field. At first this was a total surprise. Later on, this was understood in increasing theoretical detail. And now, GMR is used in every hard disc in every computer. Typically, it takes a good theoretical understanding to convert an experimental discovery into practical engineering, but the initial critical discovery was by experimentalists. Both are needed. In my experience, this point is better appreciated by the experimental physicists than by the theoretical ones.

Other examples of things first discovered by experimentalists: cosmic background radiation, expansion of the universe, blackbody radiation, spectral lines of atoms, genetic inheritance (without knowing what DNA is, by Mendel), evolution, nuclear fission, planetary orbits (Galileo's laws based on Tycho's data), cellular basis of life, constancy of the speed of light (which prompted others like Einstein and Lorentz to go figure out Special Relativity), ... etc.

There is a joke in condensed-matter physics, that theoretical physicists would have discovered solids and gases, but they would never have discovered liquids. Why? Because liquids are so complicated, and they are also in a regime that is very very hard to reason about mathematically. From first principles, it's not clear how to theoretically discover that liquids exist, and if they do, what their properties are. This is not exactly true, but it is so close to being true that it gives theoretical condensed-matter physicists a lot of pause for humility. And that is the moral of the story.

 

[hardheart]

Pretty big generalization there.

I didn't mean they are all like that, but at that there are specific ones like that. Like a cadet who thought he could tell a Bde CSM what to do when he got his commission. That sort of thinking needed explanation on differences between rank and position. I know some really good young officers, just saying some of them give us a rep at times, along with built in bias from some enlisted. Most on both sides are professionals, I wouldn't suggest otherwise. Sorry for any confusion on that, back to the regularly scheduled discussion.

 

[sodak]

Gotcha, thanks!

 

[davek14]

Ya, I'm just a lowly machinist but I meet my share of desk jocky engineers. I had to call one recently and tell him why I could not make a part to his specs since the purchased part did not have stock. His reply was that he had a print in front of him for the purchased part and that it showed enough stock in that area. I told him I had the part in my hand and that there was not enough stock. He told me he didn't care what the part measured, the print showed enough stock and hung up on me. It was a (the correct) molded plastic part. You don't get precision buying them unless you pay for it.

******************************

The U.S. Standard railroad gauge (distance between the rails) is 4 feet, 8.5 inches. That's an exceedingly odd number. Why was that gauge used? Because that's the way they built them in England, and the U.S. railroads were built by English expatriates.

Why did the English people build them like that? Because the first rail lines were built by the same people who built the pre-railroad tramways, and that's the gauge they used.

Why did ''they'' use that gauge then? Because the people who built the tramways used the same jigs and tools that they used for building wagons, which used that wheel spacing.

Okay! Why did the wagons use that odd wheel spacing? Well, if they tried to use any other spacing the wagons would break on some of the old, long distance roads, because that's the spacing of the old wheel ruts.

So who built these old rutted roads? The first long distance roads in Europe were built by Imperial Rome for the benefit of their legions. The roads have been used ever since. And the ruts? The initial ruts, which everyone else had to match for fear of destroying their wagons, were first made by Roman war chariots. Since the chariots were made for or by Imperial Rome they were all alike in the matter of wheel spacing.

Thus, we have the answer to the original questions. The United States standard railroad gauge of 4 feet, 8.5 inches derives from the original specification (Military Spec) for an Imperial Roman army war chariot.

The Imperial Roman chariots were made to be just wide enough to accommodate the back-ends of two war horses.

So, the next time you are handed a specification and wonder what horse's ass came up with it, you may be exactly right.

 

[sodak]

Ohhh...I got it now.

No, you don't.

All the years I've been on this forum, it's never even occurred to me to ask if someone was an engineer or a metallurgist or whatever. The people responding to you are very knowledgeable, and I can easily recognize when they know a LOT more than I do, and I like to hear what they have to say. I learn a lot from them and appreciate their comments. I couldn't care less what degrees or backgrounds they have, they know what they are talking about. That's all that matters.

You need to get rid of that chip on your shoulder. When someone tries to stand on ceremony because "I'm an engineer", or (just as bad) "What do I know, I'm just a ...", my BS indicator gets pegged. The only thing that matters to me is the rationale behind someone's statements. In this case, EXTREMELY extensive testing puts a LOT of the arguments to rest.

 

[bdmicarta]

I think for the user the only advantage that carbon steel has over stainless is toughness.

Hopefully as technology advances we will see some more ultra tough stainless steel's that cut like demons. I think Elmax is a good start.

Well I think this is mostly correct. Some of the stainless steels contain other materials that seem to increase their wear resistance. I don't know if any carbon steels are similar. I don't know of any reason why the steels couldn't be similar in most properties except corrosion resistance, but I wonder if alloying for corrosion resistance doesn't "water down" the materials that add to other properties. I remember reading long ago where Randall thought that their carbon knives had 10% better edge holding than their stainless knives. I don't know how they arrived at that and they might not have done scientific tests, but also the different steels that they used might not have been completely equivalent in other properties.

Basically I don't care all that much for arguments of stainless vs. carbon. I will pick stainless for most of my uses but I would still choose plain carbon steel for any knife that I thought I might need toughness in.