Thread: Chisel Hardness Study, the first step.

Originally Posted by truckjohn

DW.. No doubt the Japanese workman's displeasure of sharpening on the worksite came out of the same displeasure of carrying rocks on your back...

Not so much that. Their kit in the "old days" would've been a carborundum stone and probably two natural stones. The problem for the was that it was deemed inconsiderate to be sharpening your tools while getting paid. They had all kinds of goofy hang ups about what they should or shouldn't do in front of the customer, but they were obsessed with appearing to work all the time, and working fast.

Presumably, instead of carrying extra stones, they carried extra tools in the case where they thought they might need them.

Originally Posted by D.W.

But you have to use those tools and sharpen those tools the way they like to be used and sharpened.

DW,

I would appreciate some explanation of your process... How do you figure out "What a chisel likes" WRT sharpening and usage? Perhaps it needs a thread of it's own - but I would like to hear more about this...

Originally Posted by truckjohn

On historical chisel sharpening by workmen... Practicality trumps legend... Back in Ye Olde Days - prior to 1940 or thereabouts.. The majority of jobsites had no electricity. Workmen carried all their tools on their backs... Tools are heavy... Stones are heavier... So most workmen were taught to find a good looking rock, paver, or brick - and sharpen on that... It's sufficient. No doubt the Japanese workman's displeasure of sharpening on the worksite came out of the same displeasure of carrying rocks on your back... Not to mention that water stones are quite fragile compared to India and Turkish oil stones... Cement and brick was not common in most of Japan.. Perhaps the native rocks aren't well suited towards flattening onsite as the Old Roman tradition of rubbing two bricks together to get a good sharpening stone... And thus the divergence of tradition..

just for context, the packaging that accompanied Japan Market Shapton stones 10 to 15 years ago, recommended just 3 stones for chisel sharpening
120 -- presumably to remove nicks
1000 -- to establish the bevel
5000 -- to polish the bevel

an alternate progression was
220, 1000 followed by 12000


If I recall correctly, Toshiro Odate's master traveled with two, maybe three, stones which immediately after WW2 were expensive and difficult to come by.

Originally Posted by truckjohn

DW,

I would appreciate some explanation of your process... How do you figure out "What a chisel likes" WRT sharpening and usage? Perhaps it needs a thread of it's own - but I would like to hear more about this...

* work with the chisel, and don't write off aspects of it, but rather keep using it for a while and figure it out. For example, if you like to sharpen at 25 degrees, don't instantly determine that a chisel is "too soft" or something of the sort because it won't handle 25 degrees. Try 27. Try 27 with only a tiny microbevel, which in sharpening terms, pushes the point of failure further up the bevel - at least once you reach a steepness that an edge is held.
* note while you're working what the chisel likes. If you have a fast wearing chisel, perhaps if you're cutting half blind dovetails, you'll find that if you take tiny bites, the chisel will only finish one, then you have to touch up. That may be OK (separate discussion on sharpening with various types of steels), but it may also be better to do most of the work with the chisel in bigger bites. If you're chiseling something unusually hard or abusive to an edge (cheap fibrous red oak is normally harsh on an edge given that it's not really that hard), add another two degrees to get through the job, but only in a small bevel. Make more cuts at a diagonal in waste removal than directly across the grain, etc.
* Note how the chisel edge holds up depending on where you grip it. A lot of beginners pencil grip an edge instead of holding the handle, which ends with strikes that aren't straight in as the chisel moves around slightly. In my experience, that can be pretty punishing to an edge.


Sharpening:
* Find something that works well as a one-stone touch up to continue work. Chisels that are soft will both wear and deform. You can usually cheat a little bit by using a hard stone with them that straightens the deformation, and then stropping any wire edge off quickly. Light pressure on the final strokes on the stone to thin the thickness of the wire edge. This is different than continually chasing a bevel to a higher angle by stropping on compound.
* If a chisel is unduly hard, more on the stones, less on the strop. Something like a japanese White 1 chisel will not respond much to a bare leather strop, but a chisel 59 hardness should love a bare leather strop and not be that receptive to compound (it just makes a very sharp but transient feeling edge that will leave you dissatisfied).

There's a lot more than just these few things to it, but generally learning to work with a given tool will also yield better and faster work in general than just demanding something like being able to swing a 4 pound hammer on a japanese chisel across cocobolo endgrain (the magazines like to tout torture-type test that are more in line with that kind of strategy, but they're not realistic once you've got touch with your tools and know what they'll take).

If sharpening takes too long on a chisel that needs it relatively frequently, then sharpening is probably the problem and not the chisel.



One side comment about edge geometry on chisels- there are two sources of resistance:
* the edge itself and its ability or inability to slice what it's cutting
* the wedging of the material that you're cutting

The former shows itself quickly doing something like paring very thin grain, the latter shows itself quickly when you have a very steep primary, regardless of sharpness. People sometimes favor using japanese chisels around 35 degrees, and then consequently turn to favoring "small bites" while fancying the ability of their chisels to hold a fine edge. More productive would be a softer chisel with a 25 degree primary bevel and a very small rounded final bevel that may terminate at 30. you get some of the edge holding, but without the resistance. You also get less wedging from the chisel when you're working near a marking line or in it (wedging being the force that makes it so that you start the chisel in the marked line, but through the cut, the chisel compresses the grain under the back and blows past the line - you can try to minimize that by leaving as little as possible at the marked line, but that can end up with your chisel coming out of the cut, which leads to fiddling).

I think the difference in the two above bullet points leads people to draw poor conclusions about things like paring chisels, or specialty chisels. If you're going to trim the shoulder of a tenon to a marked line, perfection of the edge becomes less important than the geometry of the bevel and predictability of the edge. You'll probably be doing it by paring across the grain (into the tenon) with about a millimeter or some large fraction thereof of wood above the marked line. A chisel with a fat primary and very hard edge probably won't work as easily through that cut as a chisel with a lower primary and a tiny secondary angle.

It's hard to just say there's any bullet point process (because there isn't), it's just playing with a chisel until you find out where it's efficient to use it and not onerous to keep it sharp. It's different for different hardnesses of steel, just as an efficient sharpening process is different (you can keep a chisel in shape with just a washita if it's hardness 60 - but not if it's 65 hardness or heavily alloyed. You can keep a heavily alloyed or very hard chisel in shape with a lot of fine stone touch ups, but the same process won't yield satisfying results with a chisel that's a little bit softer.

Thanks for that...

It kinda points me back towards "Gets the pig clean"... If the goal is to work actual wood with the tools you have - then you kinda just have to do whatever it takes to accomplish this..... If the goal is instead to stick with a fixed sharpening routine - you have to accept that the results on wood may not be what you want and you will have to reject a bunch of tools......

There's nothing wrong with either approach I suppose..

Back to Rob's study though... I am really curious about what's going on with the Craftsman chisel... Seriously... Here's a $15 chisel that's holding it's own with $100 chisels. The vast majority of chisels in that price range won't go any significant distance..... Any insights on this one? Maybe they Cryo treated it?

It's probably just a matter of choosing a decent alloy and not screwing up the heat treatment.

I think some of the hardware store chisels are intentionally made of medium carbon steel (like a machete), because they figure that the chisels aren't going to be used in that sharp of a condition, but they may do all sorts of things that would break high carbon steel at hardness 60 (open paint cans, turn screws, etc).

Even if the steel used is US made tool steel, it's only a couple of dollars worth of steel in each chisel, and most are die forged, trimmed and then coarsely finished.

The funny thing about the Craftsman name is that it's often been used for tools that have had corners cut, or that appear to be the same as better tools, but actually aren't. In this case, I suspect craftsman had someone spec woodworking type chisels (could be buck or whoever else, or perhaps a chinese maker - I didn't look enough at the study to see the era) and they were made with decent high carbon steel and hardened to about 60. If you do just that, you'll have a good working chisel.

Presumably just about everything is just stamped (or forged in a die forge, or pressed into a die would be more accurate, they're not stamped) out of drill rod and if the stock is decent, lack of fitness for use after that is just pure laziness or assumption that the market doesn't care.

I don't think anyone is cryo treating chisels unless they are boutique tools and of fairly high price. Not that it's that expensive, but rather that a manufacturer would figure even if it adds a buck a chisel, it's too much cost if the buyer isn't going to pay multiples of that (and the average craftsman buyer will have no clue).

Originally Posted by Bushmiller

Rob

Interesting addition of JP chisels. In conjunction with the fish tail set it supports the generally held belief that JP chisels tend to be harder than their Western counterparts. The deviation appears to be mid range and bearing in mind these chisels could be hand forged I would have expected a greater range. Maybe this is a testimony to the skill of the JP blacksmiths. Very interesting particularly as these chisels are not high end.

Regards
Paul

Hand forged in chisels these days involves pressing chisels into dies or hammering them in dies and finishing them with grinding dies. What we think of as hand forged (someone working freehand with a power hammer and carefully working and inspecting) isn't common. The market prefers perfectly finished chisels to hand done, anyway (kiyotada, kiyohisa, konobu, etc).

In terms of heating, if they're hand quenched, they'd be heated by eye and quenched in a common tank - the consistency should be pretty good.

re: the early comments about pressure that i missed. It counts on the finish strokes. I'm not sure how much it counts before then, but if you use heavy pressure on the last stone you use, the edge will not be as strong.

When you get into really acute angles, like straight razors, it becomes extremely important. If you try to rush your way through finishing a razor with a heavy hand, the result will not be good, and either more time on a finish stone or a lot of use of a compounded strop will be required to have a smooth edge. What actually occurs is a broken interrupted edge on the surface.

Is there a summary document for this process, or one coming?

My personal experience would be that tools like the 64+ hardness A2 chisels will not deliver (too hard, will be contrary in giving them an edge, and sensitive to the abrasive used - needs to be fast cutting - and they will cast off parts of their edge fairly quickly).

Tools like the sorby at 58 will shed their initial very sharp edge and stay sort of sharp for a while (I prefer them), but they are not ideal for paring.

The japanese chisels will win all edge tests, unless one is purely based on wear. The harder the test subjects are (comparing same hardness A2, say, vs. white #1 or white #1), the bigger the divide will be in user satisfaction.

As a side comment about sensitivity to abrasives, last year, I bought an inexpensive ($430) metallurgical microscope to examine my razor edge, as i sell razors on a small scale and always try to give people an edge that they've not experienced before - smooth and very sharp, but not harsh. Out of curiosity, I took pictures of a lie-nielsen iron (who does best with A2 in my experience - best meaning the steel is a reasonable hardness for A2, and it doesn't give up carbides or get edge defects as quickly) after sharpening it on washita. The strange thing with washita is that it seems to raise a wire edge fairly quickly, and you can work with the edge, but it never has that initial "zing", the transient slippery sharpness that you can get with other steels.

To my surprise, a picture of the A2 edge showed voids on it. Something is being ripped off of the edge in clumps on the washita. A switch over to a translucent arkansas, and guess what. No voids. Anything else, no voids. The steel cannot tolerate the washita, which is always said to be "unable to sharpen A2", but the reason for the lack of sharpness is different than expected. The common wisdom is that the stone can't cut the A2, but you can raise a wire edge with the washita over and over. Each time, it will pull chunks from the edge of the iron that are garish under a microscope (but that just lead to a lack of shine on the planed surface - tiny lines - not the type that you get with a nick, but much smaller).

I subsequently found the same thing with certain knives made of "wundersteel", that some were very particular about sharpening material and method, and some of the hardest to sharpen steels are the first to give up their initial edge -even to a bare leather strop. That's really annoying!!

It's nice to see some of this quantified, but reading through this whole thread at once, I can't organize all of it in my mind. Sometimes, it turns out different than I perceive, but in the case of this one so far, I don't see anything that disagrees with my perception/experience. Only the comment earlier that even the chisels that take and lose an edge fairly quickly, you can learn a lot from (learning to preserve the edge, learning things like the pattern of how you remove waste. Those things ultimately make you better and faster with all chisels).

Since those types of chisels (58 hardness club, let's say) do not hold a really fine edge for long, you tend to do all of your work with them at a tolerable level (which is actually quite pleasant - you free yourself from the idea that you need that transient slippery sharp all the time, which leads you to take smaller cuts to avoid the unpleasant forces of wedging that make a sharp chisel seem not that sharp), and then do a quick sharpening and do finish cuts.

Understand what you mean about the thread, given all of the 'crosswinds' it's gotten a bit frazzled at times. I've accumulated a lot of data and observations - the slide deck I'm building is currently at 140 pages with very little text.

In no particular order the things I want to do in this area are:

Add a Stanley set to my tests.

Add a Funmatsu-Nezumi made of Hitachi powdered metal set to my tests.

Test the 'winners' against a yet harder timber.

Start testing the effects of bevel angles.

Look at stone flattening methods,

Test the Sharpskate 4 jig I just received.

Take some of the 'losers' and see if I can improve them.

Do some comparisons of 5000 + grit stones.

Summarize the results and observations made in all of the above.

Use the knowledge gained to plan the phase of the study were I make my own chisels using known alloys.

etc.

Originally Posted by D.W.

As a side comment about sensitivity to abrasives, last year, I bought an inexpensive ($430) metallurgical microscope to examine my razor edge, as i sell razors on a small scale and always try to give people an edge that they've not experienced before - smooth and very sharp, but not harsh. Out of curiosity, I took pictures of a lie-nielsen iron (who does best with A2 in my experience - best meaning the steel is a reasonable hardness for A2, and it doesn't give up carbides or get edge defects as quickly) after sharpening it on washita. The strange thing with washita is that it seems to raise a wire edge fairly quickly, and you can work with the edge, but it never has that initial "zing", the transient slippery sharpness that you can get with other steels.

To my surprise, a picture of the A2 edge showed voids on it. Something is being ripped off of the edge in clumps on the washita. A switch over to a translucent arkansas, and guess what. No voids. Anything else, no voids. The steel cannot tolerate the washita, which is always said to be "unable to sharpen A2", but the reason for the lack of sharpness is different than expected. The common wisdom is that the stone can't cut the A2, but you can raise a wire edge with the washita over and over. Each time, it will pull chunks from the edge of the iron that are garish under a microscope (but that just lead to a lack of shine on the planed surface - tiny lines - not the type that you get with a nick, but much smaller).

I subsequently found the same thing with certain knives made of "wundersteel", that some were very particular about sharpening material and method, and some of the hardest to sharpen steels are the first to give up their initial edge -even to a bare leather strop. That's really annoying!!.

DW. I have heard of this very effect but have never seen pix of the edges formed when the carbides are pulled out of the matrix..

I have a very strong suspicion that sandpaper does the same thing once the initial harsh abrasiveness wears off... Several of my blades seem to behave this way - they should be very hard and durable, but they actually fail fairly quickly in real life...

But to take this back to Rob's thread... I wonder if this has something to do with the effects Rob saw from extended honing on very fine abrasives.... Some edges got a lot better (presumably from abrading the actual carbides) and some edges got a lot worse (presumably from pulling carbides out of the matrix..)

and the ultra-high purity of White #1 pushes carbides into Iron Carbide (Rc68) rather than Va, Cr, and W carbides which can run up to Rc100... In effect forming a lot of carbides that can be sharpened rather than a lot of carbides that really can't be sharpened....

Originally Posted by truckjohn

DW. I have heard of this very effect but have never seen pix of the edges formed when the carbides are pulled out of the matrix..

I have a very strong suspicion that sandpaper does the same thing once the initial harsh abrasiveness wears off... Several of my blades seem to behave this way - they should be very hard and durable, but they actually fail fairly quickly in real life...

But to take this back to Rob's thread... I wonder if this has something to do with the effects Rob saw from extended honing on very fine abrasives.... Some edges got a lot better (presumably from abrading the actual carbides) and some edges got a lot worse (presumably from pulling carbides out of the matrix..)

Paul Williams, who made the ASW plane blades at the end of the 90s -- using a M class steel (M2 if I recall correctly) -- used to maintain that the orientation of a blade to the direction a sheet was rolled had a big influence on sharpening. Orientated at 90 degrees to teh ditrection of rolling, the carbides would pluck off an edge resulting in a very prematurely non-sharp blade, orientated parallel to rolling, the carbides could be sharpened and wouldn't pluck off the edge resulting in a longer lasting blade.

Yessir on the carbides in white 1. The carbides are so small and evenly distributed that even if they are pulled out (whereas the extremely hard vanadium carbides probably are unless the abrasive has a name starting with cubic or harder), the resulting edge is good.

The effect is basically what's seen on brent beach's page showing the tsunesaburo plane iron when compared to the other plane irons. The wear is uniform, and even a dulling iron leaves behind a very clean surface.

I'll try to find my carbide picture online (if I can't, I'll just upload it to an image host tonight and post it here).

I like the simple small carbide stainless steels for the same reason. I understand that they won't tolerate as much abuse, but we're generally cutting things (with knives) or chiseling wood (with chisels).

Originally Posted by rob streeper

Understand what you mean about the thread, given all of the 'crosswinds' it's gotten a bit frazzled at times. I've accumulated a lot of data and observations - the slide deck I'm building is currently at 140 pages with very little text.

In no particular order the things I want to do in this area are:

Add a Stanley set to my tests.

Add a Funmatsu-Nezumi made of Hitachi powdered metal set to my tests.

Test the 'winners' against a yet harder timber.

Start testing the effects of bevel angles.

Look at stone flattening methods,

Test the Sharpskate 4 jig I just received.

Take some of the 'losers' and see if I can improve them.

Do some comparisons of 5000 + grit stones.

Summarize the results and observations made in all of the above.

Use the knowledge gained to plan the phase of the study were I make my own chisels using known alloys.

etc.

Rob, if you don't have one of the M4 powder HSS chisels in your collection, PM me your address and I'll send you one. I have one from stu (at TFJ), but only one. I don't use it often because it's really no better for woodworking, but I have it nonetheless. A chisel like that is handy for making infills because you can flush trim up to metal and the HSS tools seem to be really tolerant to accidentally cutting metal. Only the best white steel chisels and knives will tolerate the same thing.

At any rate, I have two other HSS chisels and only need a single chisel to do that work, which only happens once in a blue moon, anyway.

Thanks DW,

Will do. Another forum member has sent me a Tasai chisel for testing, should be here any day now.