Mild Steel Knife Performance?

S

Showler

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Jul 14, 2013
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I am curious if anyone who started making knives used a mild steel. Maybe when you were an amateur you grabbed a bar of mild steel from home depot and went to work. If that was the case how does your mild steel blade hold up? Would you say it was low performing or just mediocre.
 
Back when I worked in the ship yards I asked our machinist and a another knife nut about this. They told me that for mild steel a Rockwell harness of 45 was doing pretty good. While I can't say how it would preform, 45 RC seems awfully soft to me. It might be okay for an axe, but for a knife I think not.

It's funny that you ask, because I've been trying to convince my brother (who wants to make knives) that he ought to use a real knife steel instead of using whatever steel than he can find.






EDIT

I'll be subscribing to this thread to see what folks have to say.

What is the correct heat treat for mild steel? I've had limited success in the past heating it to red/orange hot and cooling it in lake water until cool to the touch, to make scrapers while working on boats, but I have no idea if that is anywhere close to good or bad.
 
I am just putting a shop together and plan to use mild steel to learn/prototype with but I wouldn't expect those to perform.
 
You could probably work-harden the edge through peening.
 
You could probably work-harden the edge through peening.
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It sure won't harden by heat treating. :)

It is fine for practice grinding and it will take an edge. It won't be strong, or lasting though.

Joe
 
While the links are very interesting, they don't really answer the question of a mild steel knife.

Tension bar knife? I don't know if anybody here has ever built a chain link fence, but tension bars are about the cheapest softest steel you can find. Yes, they can hold a lot of tension on them, but think about it, they only need to bridge 4 inches max and quite often much less than that, and they're 5/8"x1/4" or 3/4"x3/8" before galvanizing. Compare their dimensions and strength to something like high tensile wire, or cable or chain and you start to see just how terrible the steel is. Super soft, super cheap.


Maybe a good analogy would be bolts. Look at grade 2 vs grade 8 bolts. I'm guessing that the materials used are not the same.
 
I've made a few crude machetes out of home depot steel and it works alright for those, actually knife work though? horrible, the knives I've made for fun are brutally ineffective
 
From a knifemaker, mild still will not work. Secondly you can buy a piece of 1084 which is a proper knife steel for about the same price as the junk at Home Depot, and after all your work you can actually heat treat it and have a real knife. I am hesitant to even mention it but a good quality old file would probably even be a better choice than mild steel. Mild won't make a good knife or even a real knife at all, machete, sword, etc. 1084 is easy to use, and costs like 3-4 dollars a foot. Even for practice it's worth the cost because in the end it can actually be finished and used. In the long run, blade steel is typically one of the cheapest parts of the entire knife.
 
Trigger Happy, what was your heat treat like?

Grayzer, I think we all know that, I did have to explain it to me brother many many times before he actually understood it though haha. I'm interested in a mild steel knife mostly for academic reasons.
 
By Bronze Age standards a mild steel blade would be pretty decent. By modern standards not so much. The hardest bronzes of the day were apparently about as hard as modern mild steels. You could always attempt the superquench method to add quite a bit of hardness to the steel, but if you're going to bother with heat treat, why not go with a blade steel in the first place (like the aforementioned 1084)?

Superquench: http://www.bladeforums.com/forums/showthread.php/375478-Super-Quench-formula.

If you want a blade that will cut stuff, but needs almost constant resharpening that will wear it down to a toothpick in no time, then mild steel will suffice. For a knife that will cut stuff with minimal edge maintenance and with much greater longevity, high carbon with a good heat treat is the way to go. :thumbup:

[/armchair metallurgist mode] :D
 
I've made a kiridashi out of a scrap piece of A36 a few years ago. The entire edge-forming and sharpening process involved a coarse file, medium file, fine file, and wet sandpaper. It was sharp enough to shave, but I never tested it to see how long it can hold the edge. I eventually gave it to a friend to scrape burnt pizza bits from the oven.

If you are planning on heat treating, you may have slightly better edge retention, but I really doubt anything fancier than a kiridashi design is worth your time.
 
no heat treat, i just made them as prototypes and took them out and the woods to have fun with, didn't expect much, but a thick grind on a machete chopping some wood worked ok for me
 
i did try to chopping a clothes hanger just to check roughly how hard it was and it took huge chunks out of mu knife with no change to that hanger, if that helps at all
 
When I was stationed in the Philippines back in the day (Late 70's), the local knifemakers made most of their knives out of old automotive leaf springs. This was WAY before I was into knives as a hobby, but I had a couple of those knives and they seemed to perform quite well. Would leaf springs be considered 'Mild' steel?
 
Auto leaf springs are made of higher carbon steel that can be heated, quenched, and spring tempered.:thumbup:
 
I ground a few mild steel blades when I was learning how to grind bevels. My first blade was made of it and I still have it on my bench, it's ugly and I wouldn't expect it to have much edge stability or wear resistance, so you know what that means.....
 
Mild Steel is not a suitable cutlery steel. It might make a fine prototyping steel but if you try to sell any of them you will piss of the buyers when they find out it's not really a knife.

You would probably be better off keeping spring steel around from old leaf springs as previously mentioned.
 
G. Scott H. said:
By Bronze Age standards a mild steel blade would be pretty decent. By modern standards not so much. The hardest bronzes of the day were apparently about as hard as modern mild steels.
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Pretty much. Will it cut? Sure. Will it perform even remotely close to cutlery-grade steel? Not a chance. But if you were to design with the limitations of the material in mind (think Bronze/Iron Age geometries/dimensions) plus a work-hardened edge and you might be surprised. A lot of extra effort for a sub-par knife, though. :)
 
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