OK, before anyone thinks the title is drug-related, it’s about cracks appearing in forged tools – especially when pushing things.
It’s been a while since I’ve posted. I have traversed reddit and other forums for a little bit in the interim and I guess when I stop and think, it’s still a waste of time. It’s tempting to try to offer suggestions and then when I think about what caused me to consider the UK forum a waste of time – it was one particular interested person who asked me for information at great lengths, and I thought about it afterward – what’s the chance they’ll ever actually follow through after all failure factors are considered. Probably less than 5%. Never heard from them again, but that’s expected.
That break also gave me some time to realize if the purpose is to post things that are helpful, after this, it should be shorter blog posts and just puttering around in the background and making this more of a webpage and less of a blog. I don’t intend to market the page and have no long term goals other than just laying things out in blog posts. The ability to blog and use widgets is something I don’t want to pay for – that is, those widgets making organizing old posts more easily, and they’d still be too long and rambling. So pack that away.
I’ve made a gaggle of W1 steel chisels and I just find it’s good. I find 26c3 is great. I want great, but 26c3 is not available in rods to fully forge a chisel – it’s available in flats. Analouges like 125cr1 definitely are not as clean when you snap samples and at first, I thought “hmm…..” because it’s easy to assume a high cost steel and a lower cost version chemically similar is a matter of one retailer or maker just hitting their “mark”, so to speak. I would be the mark in that case.
However, some further looking finds that there are things like VAR steel and other remelting. VAR means vacuum arc remelting. As I understand it, the bits that are not fully dissolved uniformly (dissoluted?) end up going through a second controlled environment melt and the result is a sample of steel that actually hardens a little easier and also shows up as cleaner under the scope. Does that matter in a chisel? I don’t know the answer to that yet. But it absolutely can be seen.
26c3, by the way, is remelted, though it’s not vacuum arc – it’s the other type and I don’t remember the names. My interest in terminology and quality doesn’t go to the “if it were a category on jeopardy” level or “look smart among your friends”, but more related to what should I buy? I don’t have the time for romantic escapades into spouting the right words for everything and knowing all of the proper names (and having the t-shirts like a cool youtuber would).
WTF does this have to do with anything?
Well, W1 makes a good chisel. I want a better chisel than can be bought, and not just in shape. I think I can make a chisel that will appeal to someone with experience in terms of shape, proportions and feel. The bar in the market is low to keep manufacturing costs down.
But the combination of sharpenability and stability in the edge in heavy use should also be better. W1 doesn’t seem to be a match for 26c3. It’s almost there and maybe an insane heat treatment process would get it there. My post-forging process is already about 7 heats, sometimes 8. This sounds worse than it is, by the way. With an induction forge, these heats are probably about 2 minutes total time per chisel actually being heated, and then rest time – but if you’re doing more than one chisel, say 3, there is enough rest time to work almost continuously from one chisel to the next.
So what are the round bar options vs. giving up and going back to flat stock? O1, W1 and 52100.
52100 is not my favorite for plane irons, but I know in chisels I also don’t like it if it’s not high hardness. 62+. Below that, it’s too tough and the edge will deflect a little before breaking off – something I don’t care for and good older chisels also don’t do. If you push it, though, you can see high hardness (stronger edge, but less tolerance to bending) and less toughness.
I think W1 is lacking in toughness. It’s not difficult to get it to high hardness.
52100 hardens a little easier, but less easy than O1 by a long shot. However, this interferes with my favorite quench – brine. Brine is a bit harsh on it, and if there is anything going on in the steel that might propagate cracking, brine is going to bring it out. However, I cannot get over the feel that brine leaves in a steel – it’s a very dry excellent feel for a chisel vs. a bendy foldy whatever you may get from elsewhere, and parts of the chisels going into the quench.
And that’s the problem. it results in things like this.
a spectacular crack right along the top of the bevel. No others looked as brilliant as this one.
Figuring these things out with less shop time than normal prevents me from having any smart-alecky things to post.
Starting with less pretty 52100 from Jantz and the finding a cleaner type actually improved hardenability of the steel, but adds a level of skill needed then to avoid doing things in forging that will leave seeds for cracking that wouldn’t occur in a slow quench, and then taking some care during quenching to emphasize max hardness on the business end of the chisel and relax things just a little toward the shoulder and the tang.
Giving up on the characteristics of bring quenching in chisels just isn’t going to happen. Not only does it make the chisel more crisp, it also doesn’t stink up my shop with smoke.
I think this is a problem solvable with skill and experimenting and have hardened three more chisels after cracking 2 of 5 initially made with 52100.
Oh…I forgot, there is also A2 and D2 rod, but I’ll quit making chisels before I’d ever begin to consider those.
I’ve made another 3 after seeing this cracking and adjusted a little, we’ll see how it goes – they are hardened but need to be finished. Which doesn’t sound like much, but water hardened chisels are just a wedge out of the quench and need to be finished to flatness and size, top curvature and side bevels ground in. All of that is done with a chisel that’s already fully hard.
I’d be plenty happy with a 1 in 10 failure rate in terms of cracking if the 52100 efforts yield a measurably better chisel that’s approaching 26c3 flat stock chisels.
Brine and Forged in Fire – They Say Bad Idea
If you’ve watched Forged in Fire you “know” nothing should ever be quenched in water because all forging oils are specially engineered for your goodness and so on. There are a couple of things at play. For plane irons, which are thinner and wide and flat, I wouldn’t use brine. I haven’t tried yet, either. The thin arrangement of plane iron cools to the center quickly. On water hardening steels, it’s not quite so automatic. You’re chasing getting the steel cool and if there is a center that’s cooling slower, as the outside cools, the heat travels from the center into the outer layer slowing what the outer layer is doing.
Knives are more like plane irons, but longer. if there is a thick spine to deal with, it’s usually not at the edge and under hardening of the spine and full hardness for the last 1/2 of bevel is probably a nice compromise. On top of that, the forging that’s going on is violent and often inaccurate on the show. Questionable forging followed by brine in a knife would be a good way to “go home”, as they say on the show.
If a bench chisel is 5.25″ below the bolster, we’re really hoping for 2″ or more of the chisel that’s uniform high hardness. To me, that’s everything being within a point in that territory. We also appreciate a balance of hardness (strength) more than toughness, at least relative to that same balance in knives.
It’d be dandy if they actually provided the post-temper hardness of the results on forged in fire, but they don’t. It would be interesting to see, but for anyone actually making things, you’d also want to see a snapped sample of the final item (the show has to keep them, anyway – go ahead and break them so we can learn) so that we aren’t oohs and ahs about a high hardness sample that has grain like beech sand.
I’ve talked to plenty of other folks who have said the same as I relayed with W1 – W1 likes brine. the light cracking I have in a pair of W1 chisels is from really continuing to forge after the steel has almost entirely lost color. You just shouldn’t do that. 52100 is like that same principle, except the lower range that you have to stop forging is higher -it cannot be allowed to cool to any shade of red and still be taking hammer blows. Most information I see suggests not shaping the steel at all below 1650, and the upper range shouldn’t be above 2200F.
Does it make a difference to work in a narrower range? I don’t think so. going back to the heat timely is probably a lot like sharpening woodworking tools. It feels like you’re getting more done if you don’t stop at the first sign of declining performance in a plane, but you’re really not.
Of Making by Hand with Wood and Steel 
Don’t think of your forum posts as useless. Even if the OP may not do what you recommend, other people come back later and search them for wisdom. It turns out that the dozen other things often mentioned in conjunction with “That one main thing” are often the key to getting it to work right.
For instance… I was having problems with Arkansas stones. I scoured forums and ONE guy posted about all the trouble he had until he broke down and used oil rather than water or soapy water or “Non-petroleum base honing fluid.” Guess what? I tried oil and viola. They are different stones.
Same thing for lapping them. Everybody says SiC grit on float glass or lexan backed up on a counter top or surface plate. I had horrible problems leaving humps in the middle of the stone. Then I found the ONE GUY who posted his adventures with trying to get them flat, and he had the same problem. I ended up following his advice (sandpaper on a surface plate) and got them dead flat.
The person with the question is probably not the person who will get the most benefit out of your posts about your experiments, simply because they may not be able to understand the answer, or they may not have the control to get the result, or they may not be able to test adequately to even know the difference. But somebody will..
Thanks
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There are definitely some avid folks – I got a post out of nowhere this morning elsewhere from a guy who is doing almost the same thing as me heat treating even though he has a furnace. And he’s using similar equipment and landed on the same kind of steps and temps that I found to work best, but with a bonus – what he gets out of the furnace is no better than what he does by hand aside from a few inconsequential preferences – and he confirmed something I suspected. I see no significant sign of decarb doing what I do. Even on steels notorious for it. He sees it in the furnace, but not when forging and hand heat treating.
Which leads to the stones and your comment about oils – I have probably been asked (more when more avid talking about stones) 50 times if I tried water “because if you haven’t, you’ll like it better”. of course I did. the action of the stones isn’t right, and it’s counterintuitive – the stones don’t cut as well with water, the action feels funny and they become very glazed. this isn’t a great conclusion.
Warren doesn’t like WD 40, but it also works well on the fine stones vs. having to have a fairly sheer coat of oil, and it doesn’t actually build up – whatever residue dries just goes away on the next use. but that’s neither here nor there – the WD 40 or a sheer thin coat of low number USP mineral oil (50 or 70) just works better than water or ballistol or whatever other avoidance there is of something simple.
I saw your question re: stones. Most of the makers have a process that’s probably fast but doesn’t flatten the stones. The rotary wheels with loose grit are always going to be biased toward creating a pillow shape on the top (center above edges).
Dans are the flattest stones I’ve gotten. if a stone is really far out, I hold it diagonally to a belt sander idler but pull it straight up and down on the idler and then check and swap the x pattern before proceeding to hand lap out a small end error.
Hellish as far as silica dust goes, but if done outside or with a good well fitted mask, no problem. Smells like death or bone or something (note quite as bid) when doing it, though. A really really out of flat stone can be brought into flat in around 5 minutes total on a cheap red alumina belt.
More people would use oilstones if they had a calibrating experience from the start. A strong washita and a strop (mdf or wood if it needs to be flat crisp edge, or the buff strop) will make an edge as good as anything sold in the shape of a stone. And usually faster than most other ways.
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Thanks for the heads up, by the way. I usually count whether or not someone took advice if I give it, but I don’t consider whether or not people find the advice a year later and take it unless they contact me.
and I never get something back from people in terms of educated (or not often enough to remember) suggestions of “I saw what you posted, and here is something better”. That would be dandy.
It’s usually “Paul sellers said to do it this way. Have you subscribed to his site?”. I’m not a pro, but I’m not really a good candidate to tune into to classes aimed at the everyman.
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Most of the time we don’t actually get advice, just platitudes. I think most folks have never even tried stuff, and certainly never tested and compared things, and the ones who do get tired of saying the same thing over and over. For example, yes, I agree. WD40 is magic on my oil stones… Better than anything else I’ve tried so far. Norton honing oil is nice at the end to give a stone a light scrub to float the swarf, though.
Also, unless it’s got a big old dip in the middle, I doubt most folks have ever even checked their oil stones for flat or not. Worse, if they are “Lapping” they assume that “It is flat when the pencil marks are gone.” Nope. Not even close, especially if using loose grit. As a result, you might be only making contact with a little section of the bevel, and worse, that contour is different from stone to stone on stones that have zero give… Of course it goes slow compared to a softer water stone which quickly conforms to the work.
My next Arkansas stone experiment is to orient the lapping scratch marks across the stone rather than down the long axis… I have a feeling that one of the reasons Dan’s stones cut so fast when new is that the scratch pattern is predominately across the stone rather than along it.. Then, we eventually get around to lapping ours, and it’s usually a lot easier to go long ways, circles, or figure eight’s, because the diamond plate is only a little larger than the stone. But now, all the scratches go with the grain on a fairly hard stone with an “Inherent particle size” of around 3.5 microns.
I’ve already got a surface plate, and it’s pretty easy to clamp a whole sheet of sandpaper to it… Going crossways is easy, and it will orient the scratches across the bevel rather than along it. Maybe nothing, maybe something, but we will see tonight.
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you’ll definitely see an increase in cut speed, but it’ll be transient unless the grooves are really deep (I think you probably won’t want deep ones). Sharp arises in the stones will definitely create cutting speed if you go across them.
I usually lap my stones in circles if I do it, but more often because it allows me to turn the diamond hone sideways and avoid creating a vacuum.
That would be on a washita for example, or a norton fine india. I don’t usually wake up fine stones, but they still cut fairly finely if you address the burr. I made a post on here about it at one point a while ago.
I think you’ll find toolmakers generally like their stones to be pretty fast (I do) and the day to day stones don’t need to be quite as fast. I use an india when making tools, but it’s well settled in, and then run off the india scratches with a dans hard, and then either buff or compound on substrate. The india is a nice stone (especially the fine india), but it can pin metal particles more easily, and that’s kind of a pain, for sure – especially if you find the pinning by hearing or feeling a clicking. Fine indias are really really fast when new, and then they’re moderate speed when refreshed later (I like them when they’re not quite as aggressive but they can definitely get a bit slow, too)
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