Amazing steel vs Amazing heat treat?

Shotgun said:
There's three things to making a good knife IMO.
Good geometry both of the edge and the knife as a whole.
Good heat treat.
Good steel.

The first two are vastly more important than the third.
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Of the posts so far I agree with this one the most, but would like to expand on it.

1.0) First off, the design concept must be a good one on a fundamental level.
2.0) The materials must then meet at least a functional minimum potential.
3.0) The geometry must then be refined from general concept to be optimized for the selected material.
4.0) The heat treatment of the steel must then be optimized for the geometry and intended purpose of the blade
1.1) If the materials are increased in performance potential, the design must then be re-optimized with the upgraded material in mind.
2.1) The heat treatment should then follow suit, being re-optimized for the new geometry and intended purpose of the blade.
3.1) Continue to loop through the process as necessary to arrive at the desired mix of performance vs. price

Good design often follows the Deming Cycle ("Plan, Do, Check, Act") which is a circular process. A change in one aspect affects the others and you need to repeat the cycle to take the change into account throughout the system.

Indeed, heat treatment is not magic so long as things are done by the book, but optimizing the selected heat treatment for the specific geometry and purpose of use is the real trick, because it involves a strong working knowledge of the tasks that are going to be performed with the tool and the possibilities of the geometry change.
 
I think this is kind of a cool post. One of the things I've always wondered is why it seems like good heat treats can be hard to come by. I've done some VERY BASIC garage forging with 1065 steel. I chose it because it was recommended as a very basic heat treat for good results.
1. Heat metal in forge until no longer magnetic
2. Quench in oil
3. Let cool to room temp
4 temper at 375 or 90 minutes
5. Let cool to room temp.

I can't remember if I tempered it a second time or not but sure enough seems to have been a good HT. I say this because it holds a sharp edge or a long time and seems to be pretty impact resistant in chopping without breaking. Also it's ugly as sin and not in a. Good way. The forging book I have discusses that more difficult steels like a2 have instructions to the effect of heat to 1525 and then Decrease by 15 degrees an our for 12 hours etc. (I'm probably butchering this) point being probably not something your going to do in a fire brick forge and more a digital kiln. That in mind you would think large production operations would have the equipment to flawlessly replicate these results. So for companies know for bad HT (or unremarkable HT) of cheaper steels, where exactly are they going wrong? It seems like the process should be put the knife in the box (kiln) take it out of the box and put it in the other box (cryo cool) then put it in the next box(temper) etc etc Any knife makers or experts who could weigh in on this that would be much appreciated.
 
Well you cant really have one without the other so thats a tough question. That being said I prefer the higher end steels as they (usually) have a well done heat treat from a good company or custom maker, but I cant deny my love for the way buck does so well with 420hc. I normally hate that steel but with buck its a great performer, I would take it over any of the other budget steels any day, the way they can take 420hc (or any steel) thats generally thought by most to be inadequate and make it great is really cool to me.
 
Shotgun said:
There's three things to making a good knife IMO.
Good geometry both of the edge and the knife as a whole.
Good heat treat.
Good steel.

The first two are vastly more important than the third.
Click to expand...

:thumbup:

Couldn't agree with this more.
 
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"Steel is the heart of the blade, heat treating is the spirit" and a high performance knife is the sum of all its parts.
 
^ Thanks! I just had a thought that some of you might disagree on but, I was thinking for a "survival" or shtf/preparing blade (you might disagree, criticism and other opinions are very welcome) You don't want the super high end steels that are near impossible to sharpen, especially since you'd probably at one point would abuse the blade. At least in a long term scenario. I was also thinking to myself if my Gurkha kukri was really worth the money, I was beating myself up over the steel being sk5 and how I could have gotten something else. But the more I thought about it the more I liked it again, okay for one the balance is superb awesome for outdoor use and god forbid fighting. Two the handle is durable, absorbs shock and is incredibly resilient. Three the blade is over a quarter of an inch thick which makes it near indestructable. Four, the heat treat (Mar temper) gives it higher end steel edge capabilities and retains the toughness the simpler steel, then I got to thinking about how historically heat treat is what made it or broke it, aside from damascus and what not.
 
Balls Deep said:
...So for companies know for bad HT (or unremarkable HT) of cheaper steels, where exactly are they going wrong? It seems like the process should be put the knife in the box (kiln) take it out of the box and put it in the other box (cryo cool) then put it in the next box(temper) etc etc Any knife makers or experts who could weigh in on this that would be much appreciated.
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I am neither an expert or maker, by any stretch. But, observation makes me think it may have more to do with ruining the HT afterwards. Grinding, polishing, etc. seems to be an issue. That's my novice observation. I'd like to hear from those with more knowledge. I think you have an interesting spin-off question.
 
Balls Deep said:
So for companies know for bad HT (or unremarkable HT) of cheaper steels, where exactly are they going wrong? It seems like the process should be put the knife in the box (kiln) take it out of the box and put it in the other box (cryo cool) then put it in the next box(temper) etc etc
Click to expand...

Most factory knives by far are simply stamped out and thrown onto a conveyor belt, run through a furnace, dumped into a vat of quenchant or allowed to air cool, and straight into a tempering oven. You can find videos of it on youtube... It's basically like watching a batch of cheap hamburger patties roll through the flamebroiler at your local burger joint... with similar results in quality and consistency. :barf:

The biggest problem with this is that it can be difficult to get entire sections of blades up to the proper hardening temperature, and they are almost certainly not staying at temp long enough to get all the elements into solution (mixed together properly). There are also issues with oxidation, uneven heating if blades are touching or piled on top of each other, not quenching fast enough and tempering properly in that manner... but you get the idea.

It's cheap though, and it (usually) gets a whole bunch of blanks somewhere in an acceptable range of hardness in a very short time.

jdk1 said:
But, observation makes me think it may have more to do with ruining the HT afterwards. Grinding, polishing, etc. seems to be an issue.
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That's also true. Not only can over-heating from aggressive (very often robotic) grinding cause issues, there's also the simple fact that most production knives are tempered much softer than they really should be, simply to save wear-and-tear on the machinery.

Higher-quality manufacturers, especially those using more expensive steels, take much greater care in every step of the process to eliminate variables and maintain consistency while maximizing the steel's potential.
 
Thanks for the info James:thumbup: I didn't have any knowledge of mass knife production, but that makes sense. It also explains why there seem to be standouts like Rowen and Cold Steel who use "cheap" steel, but make it work well. It appears (at least in my personal experience) both place great importance on consistency of steel treatment. Thanks again.
 
Wanimator said:
You don't want the super high end steels that are near impossible to sharpen,
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Another myth. Some of my best, most high end steels sharpen much faster and easier than other simple steels - very little burring. I'm talking full dull to max sharpness in a couple of minutes.

There are too many variables here to argue unless you get very, very specific. Start with your requirements. Get a design for the knife that fits that. Then get a steel that will allow the heat treat to maximize it's potential. If you are thorough, it's actually quite a bit of work to really design the best knife for your requirements.

Geometry, heat treat, and steel all work together. Can't consider one without the other 2.
 
I meant without any real equipment, like on a cement block :eek: :barf: . ^ I gotcha. You should carry a means to sharpen anyhow though.
 
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Wanimator said:
I meant without any real equipment, like on a cement block :eek: :barf: . ^ I gotcha. Some steels need a paperwheel or a sander to re-sharpen without spending crazy long amounts of time. You should carry a means to sharpen anyhow though.
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Really? How much experience do you actually have? That is downright wrong. Diamonds are your friend.

Also, in a true "survival" situation, you'd be lucky to have a knife on you, let alone something to sharpen it. I mean, you don't expect to get lost, trapped, etc., do you?
 
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