Thread: Plane Insanity

Steel sounds nice at 1% carbon. it's kind of like having 10 eggs, which would've been a nice round number. We have a dozen instead, I don't know why.

Plain 1% steel like W1 and 1095, though, suffers from something referred to as plate martensite. there's not much else for the carbon to hang out with, so when you soak the iron before quench, it ends up around 0.9 or 0.95% carbon in solution or something.

I don't know what the magic number is, but 0.75-0.85 is probably much better -with some concessions. O1 only has a little more than 0.8%, but it's brittle - probably something to do with the alloying causing the structure of the steel matrix to arrange itself in layered plates instead of an interlocking lath.

So if Sharon 50100 has nothing in it, it will be really brittle. If it has 0.6 chromium in it, the chromium at that level starts to bind carbon in chromium carbides, and those don't quickly melt of you heat the steel past nonmagnetic and don't soak it.

that results in less carbon in solution and a steel that will not break by bending as easily.

Except there's little data, so I have no idea what that would be.

1095 is often described as being in case knives or kabars, but they are all something more like 50100 or 50100B (add vanadium to pin grain size and allow more careless heat treatment). I thought I had a lot of knives with 1095 in them only to find out I have a lot of knives with something called Carbon V, which you and I can't get.

I don't have wear pictures of the 50100 at hand, but do remember it had kind of a visible array of chubby carbides for how little it's alloyed. I was surprised to see that one of the irons I made is 63 hardness. It's also the only steel that I have in 0.145" and I'm not looking to forge something else into an iron (well maybe I will, but not today).

This leads to confusion then with steels like white and 26c3 because they have almost no alloying and white can have up to 1.4% and 26c3 about 1.25%. They should have more than 1% carbon in solution. I think what actually happens is the carbon excess makes a bunch of carbides that don't melt as fast as software says they do (ok, larrin thomas actually said that, too), and you end up having a steel with excess carbon in it that actually prevents too much staying in solution by having enough carbon roaming around to precipitate and attract a nice fat array of iron carbides.

The result of this control is consistency. Both with 1095 and W1. I saw W1 samples this year as hard as 71 out of the quench. they temper back to about 65, and without showing any enlarged grain, they are very hard tempered and not that great to use.

Sharon 50100 is NLA. What I really wanted was 50100B, but it's really NLA. there's one retailer selling off an old glom of 50100 mill run stock for $14 a bar (figure a meter long and 90mm in width - lots of steel for $14, but hard to figure out what to do with it at 0.145" thick. It won't spoil.

The result of getting a 63 hardness iron is right where I'd choose a fine work plane to land. It won't chip easily and the edge will stay put where a 59 hardness edge would burr. Edge life won't be long - somewhere around O1 or just slightly less. I think it costs about $4 plus tools to make an iron with it, though.

Hi David. Can you post a photo of this piece of Scottish art?

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If you're wondering what the insanity is here, I guess it's making an iron when a perfectly serviceable iron is in the plane. Albeit probably one worth $100.

the parallel iron from the Norris no 13 (that came with a non-ward older parallel iron - I cannot now recall why I put a new iron in it other than to test the steel) is next to the spiers iron here.

the spiers had seen rust before someone removed it...I think. I've not managed to get more than two completely absolutely unused turn of the century irons with stickers and such still on them.

I think leaving the mill scale on the newer iron hides the fact that it's new and doesn't look garish like a surface ground iron. the modern reverse letters are a bit dippy, but if I don't label it, I'll never know what it is within a couple of weeks and thinking "I'll remember this", learned the hard way with a bunch of unmarked irons that i really don't know what they're made from.

The decarb is never as deep as claimed on unground steel, either - this one has had the mill scale abraded off but not remotely close to any such thing as taking off 3-4 thousandths, and it tests 63/63.5 in the various strikes.

it says F on it. That must've meant something at one point. maybe some day I'll. The data sheet for the 50100 says it's fully spheroidized (makes it softer, but the carbides are bigger). Sometimes that can hinder hardening, but not this time.

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Sharon steel here was corporate raided by a dirtbag who bought the company and then assigned its output to a warehouse, according to the people that worked there. that allowed him to basically transfer asset value from the mill to his distribution business, enrich himself and then declare bankruptcy with the mill and eventually sell it. The mill's furnaces were taken offline a long time ago and it looks like the rolling mill may still be working, but it's owned by a russian company and using russian ingots (most certainly a lot cheaper).

Oh well!

Those of you who love those older kabar knives, that's where the steel came from.

camillus, ontario, etc, all used some version of this steel in their knives - 0170-6, with camillus having one with nickel removed. It's interesting that for a long time, rather than just dropping the carbon down to 0.75% or so and not alloying anything, the knife makers wanted a steel with more carbon (the edge has more bite and feels sharper, and won't roll as easily).

Ontario was the last of the lot as far as I can recall in the US, they changed out a skilled advisor who had a nifty process with salt baths and replaced that with computerized furnaces and then had problems with knives cracking, moved to 1075 steel instead (harder to screw up) and tried to boast that it was an improvement. And then the company who owned them sold the name to a knife importer and shut down the factory about a year ago, so that's the end of that for what was, here, a huge knife industry in new york.

We do have gentrified expensive knife makers in the US now, like benchmade, though. The knives are kind of ugly, very costly and wildly popular. Ontario had boxed themselves into a position where they were selling to walmart and others of the same type and probably couldn't come up with a way to make themselves more than a discount store knife in terms of reputation.

no clue yet on the iron as it's tempering. But I did find one useful thing out - it should be hard, but I didn't have to push it temp - wise.

Why? I vaguely recalled when quenching this in parks 50 (a high quench speed oil), it really needs to be pushed. So does 52100. I don't know why but that's something that just is. When there's minimal alloying, having to push temps is concerning because even doubling grain size is going to make a noticeable difference in edge stability.

However, a quench in brine makes a nice transformation without the big temperature push and the iron out of the quench hit 68. My process is slightly modified, though - it's the first part of brine that really matters. After you get below 500F or something around there, the rest does not have to occur that quickly and there's no reason to push luck there. I let the iron get a little cooler than that but transferred it over to the anvil and held it under a plate for about 30 seconds to get it to room temp and then swished it in room temp water both to get it down to room temp, but also to wash some of the salty oxide or whatever it is that's on irons when you brine them.

they get this very pretty dull gray uniform layer with no grimy quench oil burned on them, but that surface is very reactive in terms of corrosion and a lot less so if it's rinsed.

Here is a picture of the grain (for scale, this ground offcut is about 0.14" thick).

Compare that to the grain you see on forged in fire. What you're looking for here is the gray stuff with the tiny white dots. The black stuff is dirt and big shiny smudges are shear that occurs when breaking samples - i didn't give this sample much time to equalize before hammering it and it wasn't completely converted yet. By the time I hardness tested it at 68, though, it was. I'm anticipating 63 after a strong double temper at 400F. The spec sheet for the steel suggests 62 hardness at 350F temper and 60 at 400.

What I'm doing here isn't always appreciated - it wouldn't be great for a machete, but I will boldly say that on plain steels now, i can better what a furnace soak can do in terms of keeping grain small, decarb low and hitting higher hardness. And I believe this is exactly the same set of properties settled on with the better mid to late 1800s cast steel tools, because they show no significant carbide pattern despite hitting 63 hardness on cabinetmaker and paring chisels. I believe they are a steel about 0.9% carbon with probably manganese and nickel or manganese and chromium, but won't find that out until I send one off for XRF analysis. The carbon level is not detected by XRF, though, so that requires a guess based on the amount and size of carbides in the visible light spectrum.

https://ofhandmaking.files.wordpress...4/03/50100.png

bummer - lost track of time and thought I had the toaster oven on a timer. It climbed to 425 and the resulting iron 61/62 after a pretty solid dark straw temper with total tempering time of about 3 hours. Probably more practical in a plane that's not going to be used like a long smoother, anyway.

My Toaster oven died last year - I had one you could've trusted your mother's bank account information with, but the one I have now seems to get to a temp quickly and then if you're not paying attention for a few hours, it will just creep up another 25 degrees as time passes. Everything is tempered between two 3/4" thick aluminum plates for stabilization and it has a one hour timer.

Could be a lot worse than missing by 25 degrees and probably a point of hardness, of course.

But the less great thing is the prior toaster oven went for five years and was definitely on a lot of hours before losing control of itself and just running full heat all the time (600F temp ensues at that) - it was $21 shipped.

Courtesy of covid, that kind of stuff disappeared. The new one that works less well and is maybe slightly prettier, $65, and plenty of options to get almost the same functional item with more buttons for $150.

We're in an "up yours" economy at this point. "Hey consumer, we found out that there's no reason for us to offer stuff at the low end of the market without just jacking the price up on it...up yours!"