Judging Temperature by Eye

[DevinT]

Honest question and generally curious but has there been a time, perhaps early in your career or when you first started that you used a forge to HT? Or did you go straight to a temp controlled HT oven?

I built my first electric furnace at the age of 16 more than 40 years ago. At the time I was making stock removal knives. I have made several furnaces since then but use Evenheat now. My first knives were heat treated in a ceramic kiln, I made a few from pre-heat treated material like planer blades.

I made knives for a few years before I worked for two brothers named Bob and Jimmy Lofgreen when I was 16 years old. They sent their blades out to be heat treated by a commercial heat treater. They emphasized the importance of quality materials and professional heat treating. They said that the worst thing to do is to make knives that won’t cut well.

Hoss

 

[Cole2525]

This discussion of hardness for woodworkers does create a situation where if you run into woodworkers looking for a knife, they're going to want one that will sharpen like a chisel. I've had a small gaggle of older (professional) woodworkers rave about kabar's older knives and talk about how crisply they sharpen but "they're a little soft". Their habits with tools would keep them from doing anything that would break a knife, let's say, that's true 1095 and larrin would test at 8 foot pounds.

(also, the way a plane is designed the wear bevel shown above for 1084 should be curved. On a metallurgical scope of kind of low quality like mine, the light levels tell you what's flat, especially on a lazy attempt like the 1084 picture above where the iron is on the bed of the scope dead flat. To see something at the edge looking back and reflecting light is a little odd - instead of wearing in a rounded smooth pattern, it's as if the point of wear is maintaining a little burr. The dark part of the edge is the rest of that sort of scooped wear. The 26c3 picture is from a year ago or more - the wear bevel could be a different shape due to tool setup, or it could be that I put it on an incline to light the bevel. It is spectacular at holding a crisp edge that wears evenly, though - it just doesn't wear that long.

I'm not sure I follow, but are you saying that you want the edge to fail by chipping rather than rolling?
I don't have an application in which that would be preferable, but if I did, that's the only scenario I can conceive of wanting something with hardness disproportionate to toughness.
Generally I want a cutting tool to be as hard as possible and as tough as possible within reason, with considerations made for the intended use.
If an edge is to fail I'd rather it be by rolling than chipping because I find that's much easier to resharpen/requires less material to be removed from the edge.

If a tool of a given steel at a given hardness is giving you trouble you might consider the issue is the sharpening media. I haven't had any issues getting even 10% vanadium steels shaving sharp with diamond stones followed by a bit of stropping.

 

[Josh1992]

they could be even tougher. Which would be bad. I have a feeling that I could make two sets of samples over separate days that would test pretty consistently now, though.

They also might be harder too! It depends on a lot of things but some times you can squeeze out one more HRC with good heat cycles. Also you should be able to get finer grain with a furnace. I know that with carbides time an temp are just as important as the type of steel. It’s cool you got a tool that’s more then adequate for your needs with the color and guess method. It’s how the legendary katanas of Japan were made

 

[D-weaver]

I'm not sure I follow, but are you saying that you want the edge to fail by chipping rather than rolling?
I don't have an application in which that would be preferable, but if I did, that's the only scenario I can conceive of wanting something with hardness disproportionate to toughness.
Generally I want a cutting tool to be as hard as possible and as tough as possible within reason, with considerations made for the intended use.
If an edge is to fail I'd rather it be by rolling than chipping because I find that's much easier to resharpen/requires less material to be removed from the edge.

If a tool of a given steel at a given hardness is giving you trouble you might consider the issue is the sharpening media. I haven't had any issues getting even 10% vanadium steels shaving sharp with diamond stones followed by a bit of stropping.

You're on the mark - except we really don't want failing by chipping, either. We just don't want failure of any type. rolling is relatively catastrophic if it hangs on because it creates very poor penetration into wood and there's no sharpening routine that's useful that realigns an edge.

I have a picture showing the difference in context of same use - same wood, same test, relatively controlled. The first is a series of pictures of a 58/59 hardness chisel marketed in England- common brand, and not as cheap as it should be for what it is.

picture one is off of an oilstone, 2-4 are after chopping a set volume of maple marked in the same piece of wood so that each chopped pass was identical along with the total volume.

The next is another brand sold in England, O1 steel - they spec 61, but the chisels test a little harder. Like 62ish (the only published versitron result of these is over 62). This isn't going to mean much on a knife forum, but O1 steel changes edge behavior a whole lot from 59-63 - 62 is sort of a sweet spot.

The point of these pictures wasn't actually what we're discussing here, but they cover it. Notice there's little deflection in second picture even though both performed identical tasks.

The amount of time that it took to run the test sequence and the number of mallet strikes was higher for the first one in all cases. +20% or something, and then more time because the chisel doesn't stay in the cut. The real point of this work was to test four chisels and see if a method could be found to eliminate failure without increasing the amount of shoulder effort is involved - thus the stupid name for the last profile.

The edge finish is about equivalent to a 6000 grit waterstone. Notice on the harder chisel how different the damage profile looks from the same task.

if you were on a job site and someone took your chisel to open a metal can, then chisel 1 would fare much better. Chisel 2 is a much better chisel for woodworking.

 

[D-weaver]

I haven't had any issues getting even 10% vanadium steels shaving sharp with diamond stones followed by a bit of stropping.

This is sort of a side venture - this is a picture (older scope camera, same idea) of an edge - 3V finished with 1 micron diamond on wood (finer than 1 micron diamonds used on a hard surface).

I tested plane irons to see if a claim (XHP probably) in durability planing wood held up. The claim was that a proprietary iron was twice as long lasting in woodworking tools (planes, turned out to be true. Chisels, not) vs. A2 or O1, and that the steel was easy to sharpen (often claimed as easy or easier than O1)

I didn't and haven't ever found any issue with sharpening anything - including M2, 64 hardness M4, etc. They all look the same under the scope. This is true as long as one is using diamonds as the finisher, because they're pretty violent even to vanadium carbides. Where things fall apart in a razor is that high carbide volume steels first have to be hard enough not to allow a burr to form when stropping, and second, when they are, they often won't even tolerate stropping before the last bit of the edge will chip (total edge on a straight razor is 16-18 degrees. When they are prepared right, they will not dent like a consumer razor blade). So, it's not really an issue of initial sharpness, it's a matter of whether or not an edge will hold, and then with woodworking tools, will it wear evenly.

There's another constraint - I know of one company in australia making 10V plane irons. Most others won't bother because there's no real market for high dollar plane irons.

10V would last (probably) more than twice as long as O1, but it would take at least twice as long to resharpen and remove a thousandth of an inch of length, and it would accumulate more defects from dirt, etc.

On the razor side of things, steels like S35VN appear occasionally in custom razors. Razors are a weird thing - there are "pro sharpeners". I used to peruse a shaving forum and talk about sharpening and the importance of spending $20 on a handheld scope (most people fail to finish an edge when they're starting and blame the lack of the edge on all kinds of things "it's microchipping, I overhoned it, whatever". it all goes away when they get the edge finished with no visible scratches.). I would occasionally get a message from a professional sharpener about inability to set up a S30V or something similar razor so that it was sharp and wouldn't chip out. They just wanted to sharpen the razor, test for sharpness and send it out the door. I would tell them "get fine diamond media, follow it with graded chromium oxide to remove the tooth - lightly - don't strop it, send it back to the customer and tell them not to buy any more razors made out of S35VN" or whatever it might be.

I love the whole sharpening and geometry topic - in woodworking and shaving, getting something that can be set up to prevent edge damage is more valuable than anything else.

by the way, here is the XHP chisel result - sharpened on an oilstone (finished) this example was very hard, but also the chromium carbide volume was high and the stone barely cut it - the initial edge was sharper. Unfortunately, it didn't have the same type of edge strength the O1 chisel had, despite being almost 3 times the cost.

I found the claim true about "V11" (probably XHP) edge life planing in an idealized test. The chiseling claim was false, the abrasion on common synthetic stones was half as fast, and when regrinding the chisel, the grind was half as fast with a much greater tendency to be overheated and draw temper. The profile at the very end of this is a tiny rounding of the tip of one side of the edge (not both) so like a partial tiny convex grind with the bevel of the actual chisel behind it shallower so that there's not more cutting effort - with every good chisel, stopping all damage in the test was easy. With the soft and tough chisel, it wasn't easy and would've taken more edge modification, and the same with XHP.

The last set of chisels here is marketed with the terms "very tough". It's strong, but not very tough. The chisel in this last picture IS pretty slick through wood with some damage, though, because it seems to have no tendency at all to hold a burr, and I *think* chromium carbides or maybe just the fact that they're like a tiny set of teeth, makes the chisel slide through wood more easily. But I'm going with the lack of deflection before going to tinfoil hat stuff.

For comparison to 1084 and 26c3 earlier, this is the worn edge of an iron made out of XHP - sorry about the picture size. XHP has a very crisp feeling edge, and the damage is hard to notice until it's pretty significant. It has a nice quality planing wood if it can avoid damage. Unfortunately, it doesn't take too much real life impact (interrupted cuts in wood, etc) to get it to chip.

I'm not in the knife world, but would bet there was a group of people who really liked a slicing knife made of XHP on the high hardness side, but death to a knife would be soon if it was thin and used for prying.

 

[DeadboxHero]

What a weird thread, it went from asking for advice about making a mediocre heat treat work to trying to advocate how things work.

I came from nothing, I had two bricks and a map torch, then upgraded to a propane muffle with a TC to my current setup with a computer controlled electric furnace.

D D-weaver

Well, there is no comparison. If you want the best performance you're better off pinching pennies then rationalizing a mediocre process.

On a positive, note you have a good taste in microscopes looks like it has a DIC prism, nice.

I think a quality heat treat furnace might be a more pertinent priority.

I'd recommend putting your conclusions and thoughts on edge performance in a different thread so that it's not wasted.



D DevinT well, looks like you called it.

 

[D-weaver]

I'd recommend putting your conclusions and thoughts on edge performance in a different thread so that it's not wasted.

The scope, by the way, is just a cheap $400 indian top lit metallurgical scope that I got for a different reason. But I'm starting to think that anyone who really wants to refine something fit for purpose, as I've done with 26c3 and before that, older heller files (would love to get them XRFed to see if they're about as plain), it's $400 well spent (add to that needing to replace the top tube camera as the first one couldn't work with windows 10 due to lack of power management issues -that's the difference between the kind of grungy pictures and the later big clear ones. That was unexpected and it sucked).
-------------------------------------------------------------------------------------------------------------------
I really don't know enough about what people do with expensive knives to talk about edge retention.

if I sound overconfident about my results with 26c3, it's probably because I've never made a chisel with it that doesn't hold up better than all of the commercial chisels above in a side by side test.

I've never gotten feedback from any professional woodworkers (I ping them for negative feedback, not positive) other than the fact that the edge retention is better than any of the chisels that they have and that the steel is easy sharpening (it is -it resists nothing).

I get it now, Devin has seen a lot of things - he's thinking about selling knives and relaying thoughts from people selling knives. He also must think larrin's test results of my O1 and 26c3 coupons were a fluke (they weren't).

1095 (i scribbled those in) and 1084 results were bad - I solved them on my own. How well? I don't know. Easily well enough for woodworking purposes.

Compare those to here, but adjust perhaps for toughness at 62 hardness as one end of my samples was in tongs, which created hardness a point to a couple of points softer where the tongs were on the sample, as I recall.

I don't have any of the problems being imagined elsewhere here, though. it would be just dandy if there was a page like this for woodworkers, but there just isn't anything there as the knife crowd has critical mass because there are legitimate users and a whole bunch of people who just like knives and want them to have specs. the latter part really isn't there for woodworking, and the legitimate users of woodworking tools tend to stop buying once they have what they want.

You see my comments above about testing plane iron edge life (or maybe not) - one of the reasons that I was happy that larrin came along was because 6 months or a year after I posted results of plane iron edge life, I took a lot of crap about how the tests couldn't be accurate. Nobody wanted to do them. The results were almost identical in terms of proportion (within only a couple of %) of Larrin's catra tables - except for O1.

I tested only commercial irons for that except for O1, but then conceded to compare my iron against an O1 iron in a wear test. The commercial iron was slightly harder (62-64 claimed) but mine lasted about 5% longer in feet planed in the same wood alternating the two.

I made one 1095 chisel in the past - it was a poor performer, but larrin's toughness/hardness charts show no great reason to choose it over 26c3, so I never investigated it until the goading here.

I guarantee if I sent another set of individually done samples of 26c3 to larrin, they would be the same - maybe slightly more consistent, maybe nominally better or worse by a small amount. It would only make people angry here. Plus, who in the knife market really cares about plain carbon steels? One of the reasons I haven't been here much before is the discussions tend toward coarse carbide steels, which are not so good for woodworking. Or 3V, which performs poorly in chisels at 59 hardness, just ok in plane irons (it does have pretty good edge life compared to more basic steels, but i suspect AEB-L at higher hardness is a much better choice if someone needs to go cork sniffing - that I can't do.

While it may seem like an all-for-nothing thing, out of it, I've:
* solved the issue to a practical level and past a little bit for my purposes with 1084
* I cut an iron out of 1095 and will compare it in the next few days - I suspect that will be solved
* I now have a HT suggestion for AEB-L. there's just nothing I could conjure up to get that into high hardness even if low toughness was tolerable
* It's been quite a bit of fun for me

I'll get samples tested somewhere for 1095 and 1084, but in the interest of having a comparison once I get a furnace. I'm super pleased with the 1084 results in showing toughness at high hardness, but I'm also struggling to figure out a use for them - maybe they're the answer to my question asking for 1095 cro-van, which I asked for to patch the leaks in my 1095 results, as dotted above.

Devin can think whatever he wants about me (actually, anyone can). In his market, there's nothing for him to learn about me. If I ever start to make knives and buy a furnace, I'll have plenty to learn from what he's writing about.

 

[DeadboxHero]

The scope, by the way, is just a cheap $400 indian top lit metallurgical scope that I got for a different reason. But I'm starting to think that anyone who really wants to refine something fit for purpose, as I've done with 26c3 and before that, older heller files (would love to get them XRFed to see if they're about as plain), it's $400 well spent (add to that needing to replace the top tube camera as the first one couldn't work with windows 10 due to lack of power management issues -that's the difference between the kind of grungy pictures and the later big clear ones. That was unexpected and it sucked).
-------------------------------------------------------------------------------------------------------------------
I really don't know enough about what people do with expensive knives to talk about edge retention.

if I sound overconfident about my results with 26c3, it's probably because I've never made a chisel with it that doesn't hold up better than all of the commercial chisels above in a side by side test.

I've never gotten feedback from any professional woodworkers (I ping them for negative feedback, not positive) other than the fact that the edge retention is better than any of the chisels that they have and that the steel is easy sharpening (it is -it resists nothing).

I get it now, Devin has seen a lot of things - he's thinking about selling knives and relaying thoughts from people selling knives. He also must think larrin's test results of my O1 and 26c3 coupons were a fluke (they weren't).

1095 (i scribbled those in) and 1084 results were bad - I solved them on my own. How well? I don't know. Easily well enough for woodworking purposes.

Compare those to here, but adjust perhaps for toughness at 62 hardness as one end of my samples was in tongs, which created hardness a point to a couple of points softer where the tongs were on the sample, as I recall.

I don't have any of the problems being imagined elsewhere here, though. it would be just dandy if there was a page like this for woodworkers, but there just isn't anything there as the knife crowd has critical mass because there are legitimate users and a whole bunch of people who just like knives and want them to have specs. the latter part really isn't there for woodworking, and the legitimate users of woodworking tools tend to stop buying once they have what they want.

You see my comments above about testing plane iron edge life (or maybe not) - one of the reasons that I was happy that larrin came along was because 6 months or a year after I posted results of plane iron edge life, I took a lot of crap about how the tests couldn't be accurate. Nobody wanted to do them. The results were almost identical in terms of proportion (within only a couple of %) of Larrin's catra tables - except for O1.

I tested only commercial irons for that except for O1, but then conceded to compare my iron against an O1 iron in a wear test. The commercial iron was slightly harder (62-64 claimed) but mine lasted about 5% longer in feet planed in the same wood alternating the two.

I made one 1095 chisel in the past - it was a poor performer, but larrin's toughness/hardness charts show no great reason to choose it over 26c3, so I never investigated it until the goading here.

I guarantee if I sent another set of individually done samples of 26c3 to larrin, they would be the same - maybe slightly more consistent, maybe nominally better or worse by a small amount. It would only make people angry here. Plus, who in the knife market really cares about plain carbon steels? One of the reasons I haven't been here much before is the discussions tend toward coarse carbide steels, which are not so good for woodworking. Or 3V, which performs poorly in chisels at 59 hardness, just ok in plane irons (it does have pretty good edge life compared to more basic steels, but i suspect AEB-L at higher hardness is a much better choice if someone needs to go cork sniffing - that I can't do.

While it may seem like an all-for-nothing thing, out of it, I've:
* solved the issue to a practical level and past a little bit for my purposes with 1084
* I cut an iron out of 1095 and will compare it in the next few days - I suspect that will be solved
* I now have a HT suggestion for AEB-L. there's just nothing I could conjure up to get that into high hardness even if low toughness was tolerable
* It's been quite a bit of fun for me

I'll get samples tested somewhere for 1095 and 1084, but in the interest of having a comparison once I get a furnace. I'm super pleased with the 1084 results in showing toughness at high hardness, but I'm also struggling to figure out a use for them - maybe they're the answer to my question asking for 1095 cro-van, which I asked for to patch the leaks in my 1095 results, as dotted above.

Devin can think whatever he wants about me (actually, anyone can). In his market, there's nothing for him to learn about me. If I ever start to make knives and buy a furnace, I'll have plenty to learn from what he's writing about.

I recommend starting a YouTube channel, its a nice place to build an audience and share your thoughts and ideas.

You essentially build your own platform and can speak freely to people about your thoughts and ideas which can build an audience.

I don't think you will get the desired engagement here from asking pseudo questions looking for specific answers to elucidate your ideas.

 

[D-weaver]

So, this question has nothing to do with the heat treat cycle. I have gotten good results tonight in 1095, but for some reason, there were a few nagging spots on the plane iron that I made.

Separately, I guess his part does have to do with it - the 1095 I'm using has a little bit of chromium in it and it seems to grow grain at a tiny fraction of the speed of my 1084 samples.

Back to the issue at hand. I'm looking on the surface of wood (outcome based testing vs. specifications) and I see several odd areas of different finish. I don't really ever see this. They don't rise to the level of being notches in the steel.

And, I find this - this is at 1/2 the magnification of the other pictures and that shiny area is about 5 thousandths of an inch in width - not small at all.

Is that poorly distributed chromium? If it is, would something that's not the same as the rest of the steel around it really be resolved by a 15 minute normalizing cycle? Or is this just something one wouldn't expect to see in good steel.

This steel *was* heated past critical and then annealed in vermiculite (not really annealed, but you know what i mean - it cooled in vermiculite).

Then it was subjected to thermal cycling and then heated a moderate amount past nonmagnetic (not to bright orange or anything) and quenched.

I've hardened probably around various items to date, and I don't check all of them under the scope, but I've not seen this.

I am pleased to see an appreciably large group of carbides for 1095, but they're well distributed and small - but this large shiny spot is bizarre.

 

[D-weaver]

I snapped samples from a thin strip that I'd cut adjacent to this plane iron, confirming that I'm not creating samples with large grain.

This is one - 0.1" thickness bar. See the silvery spots.

Again, I'm reliant on the steel being delivered with good uniformity since I'm not even normalizing, but I"ve never seen this in a snapped sample. Luckly, I'm about out of this bar.

Hard to complain about the grain size for a steel that was heated 7 times, but easy to complain about those shiny bits.

 

[Bühlmann]

I'm not a metallurgist, but those shiny bits look a lot like mechanical slippage or smearing from shear forces. What else do you think they are?

 

[velegski]

Getting confused with the purpose of this thread. Are you looking for better steels for edge retention. Which wood working tool are you trying to make better. And why are you limiting yourself to just these steels. Tool manufacturers are using variety of steels depending on tools intended use.
PS. FYI If you are trying to start a fued between Devin T And Larrrin Thomas You might find it difficult. I suspect the doctor was inspired by Devins T's quest for better steels. He probably learned alot running around his dads shop

 

[D-weaver]

I'm not a metallurgist, but those shiny bits look a lot like mechanical slippage or smearing from shear forces. What else do you think they are?

there's no shear on the end of the plane iron (the picture with the strange looking wear and the carbides sticking up) - it's literally just cut from bar stock and heat treated and then worn down. What do I think they are? I have no idea - I've looked at hundreds of plane iron edges and I've seen coarse carbides in cheap steel, but I've never seen anything like that. I think the composition in that spot is actually different.

planing wood is almost as gentle as a catra tester - there's very little in terms of lateral forces. In fact, the distances I plane in wood with given steels almost perfectly match the results that larrin later posted with a catra tester (which shouldn't be a surprise).

I'm kind of throwing this 1095 question out there as long ago someone advised me not to buy it for anything important. They'd had a bad experience trying to find consistently good 1095 stock and asserted at the time that it was mostly coming from overseas and not from european, japanese or american mills. I sort of wrote off their opinion, but in this case, they may be right. This isn't the cheapest 1095 steel you can find by any means, but I don't know what mill it comes from.

Since nothing has moved at all in this steel, just cut and heat treated and very little of the latter - just heats and cools in open air at the slowest and then quenched, I'm wondering if this is more common (I rarely use 1095 - it's never used in woodworking tools commercially made either - even those are getting thin on the ground with oil hardening steels because nobody wants to heat treat anything other than hair hardening steels in anything that's finish machined).

 

[D-weaver]

Getting confused with the purpose of this thread. Are you looking for better steels for edge retention. Which wood working tool are you trying to make better. And why are you limiting yourself to just these steels. Tool manufacturers are using variety of steels depending on tools intended use.
PS. FYI If you are trying to start a fued between Devin T And Larrrin Thomas You might find it difficult. I suspect the doctor was inspired by Devins T's quest for better steels. He probably learned alot running around his dads shop

Absolutely not - part of the problem is I came into this a little bit blind. Here's why - I've come up with a bunch of stuff for woodworking that hasn't been published before, but it's useful. I like to experiment, then get outcomes, then work backward to solve problems. I don't have a furnace. Cost isn't the barrier, curiosity is at this point - I'll get one eventually. these tools that we use in woodworking (older - the skill to heat treat water hardening steel in production woodworking tools is essentially gone - this isn't just a matter of heating something quickly and keeping it straight and then finish grinding flat things - the skill was part of a whole cycle of things that was established over about 250 years when the first all steel tools started to appear. the whole thing is encompassed in making somewhat irregular shapes and then heat treating them and grinding by eye).

What sparked this is that the best chisels that I have, other than the ones I've made, are from the 1800s. Nothing current matches them. They are not complicated steel, they are just very fine grained and sharpening stones don't really reveal anything about them.

So, I started making tools and seeing if I could replicate their feel and performance, and because I didn't read too much, I don't do what a furnace does. Eventually, I was passing around tools and started getting requests to make them, but I have limited time and I limited the recipients to professional users and a few friends. Professional users can tell you useful things - nothing is really better feedback than the outcome in a cycle of actual work. Amateur users can't really tell you much. At some point, a phd chemist told me not to waste my time, and then a couple of other machinists who were on the forum and who never post, took the opportunity to have a go about how the tools were probably junk, they were probably soft, whatever it may be. the chemist asked if I would make him something in a specific size, pretty early on, and I made him what I call a "dump knife", just an offcut of steel hardened to a useful hardness for general woodworking tasks - In O1. He sent me an email back and said "I will pay you any amount of money to make a slicing knife that cuts like the small knife that you sent me as well as a paring knife for my wife that she loves the shape of, but it's terrible steel". So, I made him both in O1. I told him he may eventually break it (it's extremely thin, I can harden O1 pretty well and do it a lot - by eye). I get regular comments from him about cutting half frozen venison or meat that's tough and "why doesn't someone market a knife like this". (I think the fact that it could be broken with poor use is the answer to that).

A little more goading and I declared on a woodworking forum that I may not have had any materials tested, but the chisels I make are not more than a point apart by my estimate, and if they are, I can feel it (that is true - they are right in the middle of the same hardness as a bunch of different sharpening stones - if you have some known tested tools, you can tell quickly about how hard a plain steel is).

I had been reading larrin's site, delighted to shove my plane iron test results back at the folks who don't like the company who made the plane iron that tested the best, I got his book, I eventually joined his patreon and he is local to me. The chemist I'm menotioning has a bunch of industry connections for all kinds of stuff, so he can just get stuff tested for free (XRF, hardness, whatever), but I don't have that. He's retired now and that's getting harder for him to find, too. So, since larrin is local to me, I asked him for information about a local place that would be able to do hardness testing. I didn't at the time really want larrin to do the testing because I don't think there's a whole lot of interest in plain carbon steels in knives - I think there's not much money in it based on what I read. Woodworking is kind of the same - there is a layer at the top of bringing new things out that will sell a lot of stuff at a better margin and everything else becomes sort of commodity and there's no reward there. I didn't ask larrin about that part. I've had excellent results with O1 and 26c3 in use, so I sent two sets of samples of those (larrin said he'd test them - I still kind of wondered why someone who has much more upside in other places would take the time to do it, but so be it. I still would like to know a source for testing that I can just pay).

 

[D-weaver]

Here's where things went sideways. I was right about hardness. None of my samples tested more than 1 point apart at the end of the coupon that I wasn't holding with tongs (and probably in the middle). My 3 26c3 samples tested on average better than the chart of 1475F austenized results tested (for a combination of hardness and toughness). My O1 samples tested a little harder than expected, but they were close to the toughness curve. I was pleased to find that - the coupons are harder for me to get right than larger tools because they overheat quickly, so I expect the tools might be a little bit more consistent.

I later, without thinking much, just sent three other steels hardening and tempering exactly the same way - well, two out of the three. The results were poor. I was disappointed, but as much as I like to see if I can figure everything out, sometimes you have to grow up, and I felt like that would be a good time to do it - shelve the idea of experimenting with those two to see why they want something different.

I thought there may be some hobby knife makers on here who do the same thing - use a forge and do it seriously, but it appears all the way around, I was wrong. I'm interested in the forge heat treat - Devin and Larrin look like they are not and they are trying to help me by pointing me in a direction that they think is more useful.

Larrin hasn't been effusive in any of this, so I don't want to make it out like there's been a whole lot of back and forth - he's pretty much said what he says publicly, and I'm thankful that he's written as much as he has because a whole bunch of the little things he's written about other than forge heat treatment are why I can get good results with O1 and 26c3. O1 is a weird case for tools, because if you buy good stock - and most of what's supplied by industrial supply is good stock, you can just shoot it past the temperature in a really high heat forge really quickly and evenly and get a very useful result - a result useful to woodworkers. that's all I did with a plane iron that I tested that outperformed a commercial plane iron of the same alloy.

I used what I learned from larrin to thermally cycle O1 and 26c3 and improve both. I've never made anything I'd consider good from 1084 or 1095, but I sent samples anyway - that was lazy and stupid.

so, rather than to address solving those, I asked a question on here out of the blue about 1095 with chromium and vanadium to see if those would like what I do with O1 and 26c3, which is quick and just part of the making process. 3 thermal cycles take about 5 minutes and the final heat and quench is a minute or two. that's convenient. That's pretty much it.

What doesn't translate too well is that woodworking tools live and die with what occurs in the last 4 thousandths of an inch or so. tough steels sometimes don't do better and sometimes worse than less tough if there are other variables to manipulate. This causes a problem here because I'm guessing you can't say "well, I'd be happy with half of the toughness of alloy X as long as I can nail the upper end of the hardness range". I think this is the opposite of knives, but I don't know - for fine slicing knives, I'm sure you can't be as happy missing a hardness target but still being on the toughness curve.

I want to have samples analyzed, but I want to experiment and get them analyzed. I've given up on the idea that other people are forge heat treating -there's no economic incentive to do it -I think it's learnable, but I don't think it's very easily teachable and that makes it a big speed bump for anyone wanting to make knives. I'm not making knives.

I'm a little stiff about all of this because my results with 26c3 don't vary much, I haven't had a single person not say that the 26c3 chisels aren't the best that they've used (better than anything offered commercially - there's a lot being made for boutique woodworking, but outside of better examples of japanese tools, the bar for the metal parts is not very high).

I am also a woodworker who uses hand tools almost entirely - I like the hands on part of everything. *that is the drive here, to see how well forge heat treatment can be done*. I can't do XHP like a furnace (I like XHP), I haven't had anything special in 52100, but I don't like the edge toughness for woodworking and haven't ventured in to trying to get a pearlite structure to start and drive it to very high hardness at lower tempering temperatures, and I can't do AEB-L for anything other than abrasion test mules (they're not the hardness I'd like - they're hard enough to test, but all I can figure is that their fineness and abrasion resistance means they have a lot of potential if done properly and to a higher hardness - to be a lot like a carbon steel).

that's the whole story. I personally believe 26c3 is easy to do in a forge if you're willing to sit with it and do everything evenly. I think O1 is, too. 1084, I can now do OK but I'm not going to send test coupons to larrin and continue what looks to be a spat (and it's not larrin's spat - larrin just gave me objective results) - but what I learned with 1084 is that you have to be very quick on watching color as it doesn't have the quench heat forgiveness in a forge that O1 and 26c3 have.

Now, after getting all of the grain size bits figured out and having samples with excellent hardness and small grain, at the tail end of this, for the first time in all of the heat treating I've done, I think I'm seeing something that shouldn't be there in 1095 sheet.

I started this thread because I was pretty happy about solving 1084 - it didn't take much, but I noticed that what I think I see is the color when it goes nonmagnetic is a little bit more dull than 26c3. It could be coincidence or maybe it was in my mind, but when I backed off by eye with color, suddenly I can manipulate what I want to and it's not too hard.......as long as it's never allowed to overheat once you get to setting the grain and then doing thermal cycles.

there are other little bits and clues in woodworking tools that have led up to this, like seeing some reasonably good tools for woodworking use basically die forged and then induction heated and quenched with a splash. Are they doing normalizing somewhere else, or are they taking advantage of alloying (chrome vanadium alloys) to have success? These are all things that nobody is going to answer, I guess, but I can't get a 1% CV steel...

.....and that's what ties this all together - not knowing that much about how little forge heat treating is liked, when I got bad results with 1084 and 1095, I went for what I think is the industry fix to allow some sloppiness on my end and to do the heat treatment the same way that I do 26c3 and O1.

.............


phew...so why not look into other steels? AEB-L has the potential at high hardness to be something interesting. The rest, a lot has to do with exposure and knowing that certain specs of the tools were better, but in use I didn't like them as much (in real use, not just a spec test). I didn't even like the same thing in real use (XHP tested fantastically in an idealized test) as I liked in my own tests.


by the way, the best performer in a like-actual use chisel test - that I ran a couple of years ago was japanese white steel. It's low toughness. It stands out as far superior for woodworking with a chisel. I have pictures of the edges of various chisels and a sort of routine japanese professionally made chisel set that I have (one that cost little used) battered everything commercially made here pretty badly.

 

[D-weaver]

(I've got two more plane irons waiting for thermal cycles this evening to make sure that what I found with 1084 I can do identically three separate times. If I can in terms of performance perception for woodworking - same hardness on the stones, same burr characteristics, same edge performance - then I'm kind of done. After that, like with 26c3, to get actual testing done later is just a matter of seeing what the results mean in numbers. but the numbers don't matter if they don't change woodworking outcomes).

 

[DevinT]

Nothing says success more than a bunch of bad results.

Hoss

 

[D-weaver]

Nothing says success more than a bunch of bad results.

Hoss

Point to the ones in the steels that I use, Devin. Point to the furnace results that match the 26c3, too. I keep seeing schedules showing 6-10 ft lbs of toughness for 26c3 at 62 hardness. All of my samples ranged from 10-14 at an average just under 64 hardness on at least one end and probably the centers.

That's what I was looking for - actually, I was looking for the hardness. Larrin is interested in the toughness - I thought at the time when he said that "ok, whatever you want to see" - I can tell when toughness is a problem in tools.

I think from your assessment that you never had an instance where you challenged yourself to get good at the process of forge heat treatment for a few steels and you understand it as trying to imitate a furnace. I followed a process for 26c3 that wasn't that, it was quick heats.

You've managed to avoid facts with the first two - it's tiring. Because I have no agenda other than I like to do things that are based on hand and eye. Even if I can manage to learn to do them consistently for a small menu of steels, it's not practical from any perspective other than as a hobby because you can't get a wage worker to pay attention enough for a shift, but they can follow a furnace schedule in an industrial setting. I think you're suffering from believing you know a lot of "can't". I'm sure you would've said before I submitted the first set of samples a "can't" for every one of the specs - consistent hardness, toughness varying a little bit more, but all acceptable - all at or above the test results for a furnace.

Your can't answers all had to do with selling and knives. I think you can't process anything that doesn't match what your experience is, and your post talking about who gets more likes was kind of eye opening.

I "can't" get interested in searching for likes.

 

[DevinT]

Point to the ones in the steels that I use, Devin. Point to the furnace results that match the 26c3, too. I keep seeing schedules showing 6-10 ft lbs of toughness for 26c3 at 62 hardness. All of my samples ranged from 10-14 at an average just under 64 hardness on at least one end and probably the centers.

That's what I was looking for - actually, I was looking for the hardness. Larrin is interested in the toughness - I thought at the time when he said that "ok, whatever you want to see" - I can tell when toughness is a problem in tools.

I think from your assessment that you never had an instance where you challenged yourself to get good at the process of forge heat treatment for a few steels and you understand it as trying to imitate a furnace. I followed a process for 26c3 that wasn't that, it was quick heats.

You've managed to avoid facts with the first two - it's tiring. Because I have no agenda other than I like to do things that are based on hand and eye. Even if I can manage to learn to do them consistently for a small menu of steels, it's not practical from any perspective other than as a hobby because you can't get a wage worker to pay attention enough for a shift, but they can follow a furnace schedule in an industrial setting. I think you're suffering from believing you know a lot of "can't". I'm sure you would've said before I submitted the first set of samples a "can't" for every one of the specs - consistent hardness, toughness varying a little bit more, but all acceptable - all at or above the test results for a furnace.

Your can't answers all had to do with selling and knives. I think you can't process anything that doesn't match what your experience is, and your post talking about who gets more likes was kind of eye opening.

I "can't" get interested in searching for likes.

You talk too much

Hoss

 

[Bühlmann]

there's no shear on the end of the plane iron (the picture with the strange looking wear and the carbides sticking up) - it's literally just cut from bar stock and heat treated and then worn down. What do I think they are? I have no idea - I've looked at hundreds of plane iron edges and I've seen coarse carbides in cheap steel, but I've never seen anything like that. I think the composition in that spot is actually different.

planing wood is almost as gentle as a catra tester - there's very little in terms of lateral forces. In fact, the distances I plane in wood with given steels almost perfectly match the results that larrin later posted with a catra tester (which shouldn't be a surprise).

I'm kind of throwing this 1095 question out there as long ago someone advised me not to buy it for anything important. They'd had a bad experience trying to find consistently good 1095 stock and asserted at the time that it was mostly coming from overseas and not from european, japanese or american mills. I sort of wrote off their opinion, but in this case, they may be right. This isn't the cheapest 1095 steel you can find by any means, but I don't know what mill it comes from.

Since nothing has moved at all in this steel, just cut and heat treated and very little of the latter - just heats and cools in open air at the slowest and then quenched, I'm wondering if this is more common (I rarely use 1095 - it's never used in woodworking tools commercially made either - even those are getting thin on the ground with oil hardening steels because nobody wants to heat treat anything other than hair hardening steels in anything that's finish machined).

I was referring to your "snapped" samples in the pic from post #50, immediately prior to my reply in post #51. If you have failure samples, they were subjected to shear forces to impart the failure.