Traditional Folders & Fixed: Steel 101 - Geometry & Heat Treatment

[KBA]

If you have been here long enough and have made your way through the other sub-forums I am sure you have seen the steel battles; "This steel is better..." or "No, this one is."

If you read through the threads long enough you will finally see the veterans trying to help out the young-ins by expressing the truth: heat treatment and blade geometry are more important.

I thought it may be beneficial to bring that conversation here to the porch. Well, in all honesty, I wouldn't mind a deeper education and hearing your opinions on the steels used here, folders and fixed.

Some questions to ponder on to those who use their knives.

For the green ones, what is blade geometry? Grinds, Bevels, Thickness...
What do you all consider "traditional steel?"
What blade geometry works best for certain task?
Who produces certain steels at the right heat treatment and who do you believe produces at a poor treatment? (Custom and Production)
What steel fixed blade knives and folders do you like and do not like? Why?
What steel would you like to see used on "traditional" folders and fixed blades both that are not being used? Why, other than personal opinion or "they didn't use that in the old days."?
Whose steel is over rated? Why?
Ways of knowing the heat treatment is poor or off?
What Rockwell levels are best for certain steels?

I'm open to any conversations focused on steel.

I'm not trying to start a steel battle. I believe the folks here can carry on a conversation that won't bring it to such.

Pictures are always welcome to use as an illustration of geometry and their uses.

 

[Cambertree]

Ooh, this one usually ends in tears...

But I think you're right Brett - the quality of discourse here on the porch is such that if these questions can be dealt with on any forum civilly and in a way that advances learning, and facilitates further understanding, it's here.

You've framed some great questions actually.

It's late here now, so I'm gonna turn in, but I'll be back later to read with interest, especially from the makers, sharpeners, forgers and heat treaters...

 

[boy&hisdogs]

Carbon steels take a better edge and hold it longer.
Stainless steels are stainless for those who like a shiny knife or often work with corrosive materials/enviroments.

Most name brands have good enough heat treats.

In my experience, it really is just that simple.

 

[KBA]

Thank you for your opinion on carbon vs stainless and production heat treatment.

 

[Woodrow F Call]

I find stainless can take a edge as good as carbon. I'm just nostalgic enough to like patina'd carbon knives better.

Heat treat, thickness, and geometry is generally more important than metal to get an edge. Steel makes a difference in longevity though.

 

[netguy1999]

Personally, although I really like the look of patina on some blades, I gravitate more towards stainless. I like to use my knife in as many situations as I can and that includes food preparation at work. To me, stainless just seems to be the best choice for this due to the corrosive nature many foods and the transference of taste from the blade to the food. I may not have an in-depth knowledge of steel, but this has been my practical experience.

I think this will be an interesting thread to follow and I am sure I will learn a great deal from it. An excellent thread to start, Brett!

 

[boy&hisdogs]

Good points, I guess I jumped the gun a bit and didn't consider all the angles.

The vast majority of my stainless experience has been with China stainless, while my carbon experience has been with name brand traditional knives.

Thinner blades and taller grinds make a knife FEEL sharper, which is probably half of what makes me prefer carbon steel knives. By far my "sharpest" pocket knife is my Opinel, which was my first carbon steel knife and what made me fall in love with carbon steel in the first place.

I think many people, especially on the internet, completely over-blow the differences between steels of the same catagory though.

If one knife comes in 440c and another comes in 420HC I call that close enough, and you should just choose the knife with the features you like (shape, size, pattern, etc) and forget the minute differences between the two because you probably won't even notice them in real life.

Same goes for ats-34 vs cpm-154 vs S30V or whatever other super steels. If you get choices in the exact same knife, then go ahead and be picky, but if you're talking about two different knives that use similar steels, then the size/shape/pattern are probably more important than which steel is ever-so-slightly better.

10XX vs 400-series vs super steel is an important choice, but beyond that I think most people will be happy with most steels if they can get the all the internet bench-racing out of their heads and just use the knife.

But of course this is coming from a user's point of view, not a maker or collector.

I haven't noticed a difference in taste and I don't store my knife in a bucket of salt water. I can't afford designer steel knives anyway so my steel choice usually boils down to 1095 vs 440, and I'll choose 1095 most times.

 

[KBA]

Since the conversation has geared towards the carbon vs stainless debate let me direct it to a more specific focus.

Here are the porch 1095 is the common carbon steel, 440c and maybe cpm154 the more common stainless. Yet there are several other carbons and stainless with D2 kind of stuck in the middle.

Let's try to be more specific in the type of carbon and the type of stainless, so we can bring in steels such as M4, CPM3v, S30V and so on.

I personally appreciate a patina for my own reasons but patina is only a superficial desire to the steel I choose. The geometry is primary.

I appreciate all the input thus far. And, I do hope to hear from the makers.

Also, I know the porch is an ethos in and of itself, built on politeness and respect, but several come here needing truthful feedback on the steel they are buying. If a custom maker or production maker is not up to par to others we need to report that respectfully, knowing that could well be someone's friend or favorite knife maker.

I hope to learn through this thread.

 

[Jack Black]

I find stainless can take a edge as good as carbon. I'm just nostalgic enough to like patina'd carbon knives better.

Heat treat, thickness, and geometry is generally more important than metal to get an edge. Steel makes a difference in longevity though.

This about sums it up for me too :thumbup: I prefer carbon, but logic doesn't have much to do with it

 

[KBA]

Boy&hisdog - sorry if my post echoed yours. I was typing on my phone which takes forever and didn't see your post

 

[Buzzbait]

I'm a true believer in good heat treatment.

From my recent experience, GEC does a great job with heat treating their 1095. They tend to get it nice and hard, and I haven't had any chipping issues at their hardness. GEC also tends to put a nice grind on their blades, which I love. Kudos to GEC.

Case...... Their heat treatment, for both their surgical stainless and CV, is far too low in hardness for my liking. The edges just roll right over. But at least the grinds are thin, so they cut relatively well.

Queens D2 is the stuff of legend. D2 is just a wonderful tough steel to begin with, and Queen seems to get the hardness right. The edge on my Queen scout lasts forever. I also love how thin the edge is on that knife. As a slipjoint blade should be for most every task, my scout's main blade an absolute scalpel.

Note - I have heard that not all of Queens blades are as wonderfully thin as mine, which is unfortunate.​

I have a number of Camillus scout patterns in my collection. Camillus had a tendency to run their 420 on the soft side, and the grinds tended to be too thick. I love their scouts, but the main blades tend to give me fits.

My old carbon steel Schrade Old Timers have a nice hard heat treatment, and reasonably thin grinds.

For the record, I've never had a 420 series steel blade with a hard enough heat treatment for my liking. I don't know it's just not possible, or if everybody's just bad at heat treating 420.

 

[traumkommode]

Carbon steels take a better edge and hold it longer.
Stainless steels are stainless for those who like a shiny knife or often work with corrosive materials/enviroments.

Most name brands have good enough heat treats.

In my experience, it really is just that simple.

I have observed more than one traditional knife user/collector/whatever who had a similar opinion. I'll proffer that experience may have come from either Case's TruSharp, or something similar, or something more modern that is difficult to sharpen. In the case of Case [sic], that steel is kinda "gummy" when it sharpens. It is easy to sharpen, and to get really sharp, but it takes some finesse. It's too soft to wail on and get a keen edge, in my experience. In general 440C is more difficult to sharpen, than, say, 1095, meaning it takes longer. Newer stainless steels even moreso, hence many people's frustration with stainless overall.

A note on blade grind and sharpening - thickness behind the edge makes sharpening more of a chore. Queen and Schatt and Morgan knives all come ground pretty thick behind the edge, and that makes them take longer to reprofile. GECs are generally ground thinner, and so they don't take quite as long. So that's a second variable to combine with steel when you talk about ease or difficulty of sharpening, which reveals that it will depend as much on the particular knife and the grind on its blade as the variety of steel.

Another note on blade grind and sharpening - traditional knives with belly, i.e. spear points and clip points, usually don't have the same kind of distal taper that I've seen applied to many modern knives. The result is that the blade is thicker at the tip than at the base of the blade, and this can result in some pretty different thickness behind the edge to pay attention to while sharpening the tip versus the rest of the edge. So much so that, on some knives, I've spent 2-3 times as long to get the tip sharp right than I did on the rest of the blade, using Lansky's dubious standard stones.

I prefer a full height flat grind, and am starting to get into thin convex. I like my knives to cut and maybe to pierce. I don't have any bushcraft needs, so I prefer thin blade stock. 3/32 (.093" or ~2.4mm) or less is ideal for me. .125 is just too thick for me to want to use. But, I don't baton wood.

Thickness behind the edge has almost as much affect on cutting performance as the thickness of the blade stock itself. Stropping is very important to me, takes sharpness to the next level.

I don't know enough about heat treating to be able to speak any specifics there, but its sort of like cooking - well, it is cooking the steel. When you want to make chili and serve it over rice, it makes for a much better presentation to cook the chili and the rice separate, and then mix the two in a bowl; to refrigerate the two seperately, and then reheat in the same manner. If you want your brisket to be tender, it has to cook lower for longer. Not necessarily analogous to heat treatment, but all that to say that heat treatment matters, and the better it is, the better the blade. This is an area where custom makers get an edge because they can afford to go one blade at a time, to get a very specific result in a narrow margin. I'm sure that some heat treaters get consistent results in narrow margins, too, but think about a cookie sheet covered in cookies. Each one turns out slightly different, some are softer than others depending on where they are on the sheet, and how thick they are, and etc. May or may not be the same in a heat treat setup, perhaps someone like knarfeng who knows more about that could chime in.

I used to only want stainless steels because, when I thought about rust, I dreaded the idea. But using carbon steel more, I realized it's just not that big of an issue for me, even in Atlanta, GA where it's fairly humid. GEC's 1095 is fairly low maintenance in this climate, I just wipe it off if I cut an apple or something else wet, and then I have this really cool patina that changes over time. The patina has grown on me. I also like GEC's 440C, which gets just as sharp but with more effort, and stays sharp longer. Sharpening is as much an art form as a science, and my suggestion is to do it, and do it some more, until you start to get results you like, and then figure out what you're doing that gives you those results.

Personally, though, I wish that traditional knife makers would adopt newer steels. CPM154 is great, but I don't care for the way Queen/S&M knives feel. Spending at least $350 on a custom isn't really an option given my pay grade, because I have other financial priorities. I understand why traditional blade steels like 1095 and 440C are popular on slipjoints, and I also understand the philosophy that, "if we're going to make a traditional knife, then the steel needs to be traditional as well as the design." I even understand that a slip joint folding knife isn't designed to withstand the kind of forces that would push a steel like CPM3V to its limits...

...HOWEVER, I would love to have a slip joint or a more traditionally styled fixed blade in CPM3V, or M390, because those steels are spectacular at what they do. There are a few modern companies that make non-locking folding knives, but they aren't popular with most of the modern crowd, so they don't get steel priority. Those modern knives mostly have blades thicker than I would like, and when I hold them, I can't feel any soul in them. Some of them look to me like something Batman would carry, and I'm not Batman. I prefer the feel and experience of a traditional knife, but I would also like the benefits of some of the modern advances in steels. Kind of like how a lot of my personal philosophies and practices and self-care rituals blend old-world traditions of other lands with modern day advancements to optimize who I am. A knife with a steel that stays sharp longer and is less prone to damage will do its job better for longer. Just how my mind simplifies it.

 

[netguy1999]

Buzz, that's some great input. I would tend to agree with your assessment of D2. D2 and 154 CM are actually my favorite steels. I have an S&M in D2 and it is scalpel sharp and touches up without much effort. Likewise, I have a Tuna Valley in 154 CM with similar properties. I haven't yet sharpened my 440 GEC, but I assume it will be similar to the 154. I haven't been able to get my 420 blades nearly as sharp. Again, my opinions are anecdotal as opposed to empirically based. I'm still relatively new to collecting so I am learning more and more every day.

 

[GorillaFeet]

Others have made some good points about geometry and heat treat being the more important than steel, as long as the steel is something decent. One thing to note, if it's not too nitpicky, is that some of the 1095 used is really more like 1095CV. Although still a carbon steel like plain 10xx, the CV will have the harder carbides of those elements, with the corresponding effects on hardness, wear resistance (sharpening time) and toughness.

I would also like to see some newer steels like S30V, etc. if it could be done without raising the price too much. I think it's likely that we get so-called "lesser steels" compared to modern folders as a tradeoff for multiple blades and the more complicated construction of slipjoints.

netguy, D2 is one of my favorites also. On the other hand at one point I opted against a Queen in D2 because I had read about the thick factory grind and dreaded how long it was going to take to reprofile a thick D2 blade...

 

[choombak]

1095 has been a favorite of makers for its "field sharpening" character, no wonder its used on traditional pocket knives and ESEE continues to use it on all their fixed blades. I am not a steel snob, and much like others here on the porch consider geometry and heat treat to be far, far more important than the actual steel used. However, modern steels are a tribute to the ingenuity and innovation of mankind, and it would be great to see some high-end steels on traditional knives (S110V, M390, 20CV, etc.). Best of both worlds!

 

[netguy1999]

Although steel is important, I'm also quite interested to hear what others are using different blade geometry for in terms of tasks. After much reading, I understand what some of the different geometries have been used for traditionally, but in many settings today, those traditional tasks may not be present. I, for instance, have taken a liking to lambsfoot blades but I am pretty sure I will never have to trim a lambs hoof.

 

[boy&hisdogs]

Although steel is important, I'm also quite interested to hear what others are using different blade geometry for in terms of tasks. After much reading, I understand what some of the different geometries have been used for traditionally, but in many settings today, those traditional tasks may not be present. I, for instance, have taken a liking to lambsfoot blades but I am pretty sure I will never have to trim a lambs hoof.

I like either a full flat or gentle hollow grind for just about anything that a pocket knife would be for.

I also really like sheepsfoot, wharncliffe, or other straight edged knines for detail work, especially at the tip. If it were up to me then every pen blade would be a wharcliffe/sheepsfoot instead of a spear.

I have a mild astetic dislike for clip points because too often they get rounded off and end up looking too short for the handle. But a nice crisp clip point does look awfully good.

 

[knarfeng]

Oh bother. You pushed my button.
Let me start by saying, "complex problems have simple, easy to understand, WRONG answers". And it turns out that cutting a piece of material in twain is a surprisingly complex problem.

I am, among other things, a steel junky. Likely comes of being a chemist and a materials engineer. I've spent a fair amount of time and energy trying different knives with different blade alloys. I tested them in side-by-side cutting tests using manila rope as a medium. I also carried them and used them for everyday tasks. I wrote a fair number of threads in the Testing Forum listing out my results.

A carbide containing stainless alloy such as 440C will maintain a working edge far longer than 1095. But 1095, if heat treated to a high hardness, will hold a fine edge longer than 440C. You could substitute "non-carbide stainless steel" for "1095" in that last sentence and it would still be correct.

This assumes similar hardness and similar cutting geometries. For the purposes of rope cutting tests, that means the edge bevels have to be the same. For other types of cutting, the blade profile comes into play, including thickness of the blade above the edge, and thickness of the blade overall.

Chrome Vanadium Alloys (e.g. Case CV; Carbon V; 1095 Cro Van) : The percentages of Chromium and Vanadium are so low that the carbides which are formed have no impact on edge retention. A small amount of Vanadium is used to refine the grain structure. A small amount of Chromium is used to change the heat treat properties. The finer grain structure of such alloys improves the edge retention some, but it won't make a softer blade outperform a harder blade. The added elements also give better toughness to hardness performance.

Tool steels such as A2 and O1 are outside my ken. Never tried 'em.

PM alloys, such as S30V will SIGNIFICANTLY outperform 1095 and 440C for edge retention. M4 and Bohler M390 take edge retention to a whole other level.

Personally, I find the stainless steel which performs very close to 1095 to be the Japanese alloy, AUS8. 8Cr13MoV (Chinese alloy) performs the same as AUS8 if both are hardened to the same hardness.

In my testing
420HC < AUS8 < 440C < VG10, 154CM, N690 < S30V at 59 < D2 at 61 <<<< M4, M390.

But
A common failure mode for blades is edge deformation. So it isn't just the alloy, it's blade hardness and edge geometry. To a certain extent, you can make up for having a softer steel by using a broader edge angle. The broader angle results in more steel supporting the edge. I use 15° per side for my Buck 420HC blades. I use 20° per side for Case knives.

It also depends on what you are cutting. If you are peeling an apple, the edge is not going to deform all that much. But if you cut a harder medium such as plastic, edge deformation becomes a definite issue.

Best results for edge retention? Harder alloy with PM sized carbides. The harder alloy lets you use a more acute edge bevel without edge deformation. The more acute edge angle improves cutting performance.

I like Case knives. Even though I don't really care for their alloys. They run them too soft. But for most everyday usage, they work just fine. But if I know I'll likely be doing something significant, I'll pull out something modern with better performing, harder alloys.

 

[KBA]

Frank, thank you for chiming in. I was hoping you would. Most of the threads as stated in the OP were, refocused, though your post, and a few others. Ive used your diagrams and graphs countless of times. :thumbup:

 

[supratentorial]

Another note on blade grind and sharpening - traditional knives with belly, i.e. spear points and clip points, usually don't have the same kind of distal taper that I've seen applied to many modern knives.

They SHOULD. If they don't (and there are lots of examples that don't), the manufacturer needs to step up their game.

Oh bother. You pushed my button....

Nice post

GEC also tends to put a nice grind on their blades, which I love.

:thumbup:

...Note - I have heard that not all of Queens blades are as wonderfully thin as mine, which is unfortunate....

They have varied a lot over the years. Some thin. Some thick. Some ridiculously poor. The tapers have also varied a lot.