Does better steel get sharper?

[custard]

I don't normally join sharpening threads, but I would say that I've often noticed that the first few sharpenings of a new tool rarely bring it up to it's best. Furthermore, if I've nicked a chisel or plane iron and have to grind it right back then the same thing occurs, where it takes a couple of rounds of honing before the tool is again singing.

I wonder if the act of grinding an edge might have an adverse effect on the steel, and it requires some of the surface metal to be honed away (more than you'd normally remove in a single sharpening session) before it's optimised? Possibly some micro bluing that isn't actually visible to the naked eye (although I've experienced exactly the same thing from a cool running Tormek as well as a high speed grinder)?

This is conjecture, but if it's correct it would explain why you need to work with an edge tool for a while before discovering what it's really capable of (so all those "instant" reviews that get posted of new tools are especially useless). Furthermore it's another reason to avoid grinding right to the edge, and to try and preserve the edge by only grinding to within a mill or half a mill away from the actual cutting edge.

In industrial grinding practice, there is a phenomenon known as 'micro-cracking' which is a particular problem with harder materials (like hardened tool steels).

What happens is that the grinding generates very high temperatures very local to the action (we're talking microns here, not something you detect by keeping a finger near the tool edge whilst it's on the wheel). That causes the metal close to action to both expand (outwards), and soften, becoming slightly plastic - the bulk of the metal behind doesn't get enough heat for either to happen to any degree. The wheel passes, and the edge cools very fast, contracts, and loses it's plasticity, but can't entirely contract back to where it was because the bulk of metal behind it won't move to accomodate it. Consequently, tiny cracks form along the edge (or surface of a piece in a surface or cylindrical grinder). It's almost impossible to grind this damage away, because the localised heat applied by the grinding process just makes the same thing happen again.

In industrial practice, forced flood cooling is used to carry off the heat as it's generated (dipping in a can of water won't do!). In the woodworking situation, honing (far less heat) slowly abrades off the damaged bit. Thus, an edge straight from the grinder and honed once may seem brittle, but the brittleness disappears over three or four honings.

I'm not sure whether that's the only explanation, or whether other factors are involved, or even if it's completely irrelevant. It does seem to fit the symptoms, though.

From the practical point of view I think the practice of not quite grinding right to the edge should avoid the problem. Micro-cracking will still happen further up the bevel where it's ground, but it won't do any harm up there away from the cutting edge.

That's interesting, thanks for that.

 

[Trafalgar]

Hello,

Charles, have you ever used Hock A2 cryogenic plane irons or the Veritas PM V11? I strongly suspect if you had, your sniffy posts would stop. Both are truly remarkable steels and since steel like good old W1 is no longer made and O1 seldom if ever hammer forged to give it that good old grain structure, we need advances in steel technology if our craft is to prevail. I first bought an A2 plane iron after using a particularly ornery wood that actually curled the edge of my plane iron after a couple of passes. The hock iron did not falter. I recently tried a PM blade out of curiosity and it is even better. I don't understand the resistance to progress here. I particularly like the Clifton plane irons, but it looks like they will not continue making them. Tools cannot be hammer forged without tremendous expense, which most users will not bear, so arguing that old tool steel is best is moot since you will not pay for its continued manufacture.

Mike.

Well, I have a Hock iron in a Record 4 1/2 but alas it's O1. It's fine. It does stay sharper a little longer. It's harder steel, slightly more work to grind and slightly more work to hone. All in all it's about a wash, time-wise. Never have tried the frozen stuff.

I had a Lie Nielsen plane (a scrub plane) which of course came with A2 and I hated the cutter. I replaced the plane with a vintage Stanley. Love it. Love the plain high carbon steel, love the way it cuts, love the way it hones. I love it. It leaves nothing to be desired IMO. You can practically carve with that little bugger.

I demo'd a PM-VII chisel and while it was beautifully made I don't see what all the fuss is about. It's probably better as a plane iron. It totally did not rock my world.

So yep, I've used all these steels. I even had a mortise chisel in D2 which I loathed. I couldn't put an edge on that ba$tard with SiC sandpaper. Horrific. It never formed a wire edge just this little hump I kept chasing front to back that would never come off. Came dull and stayed dull.

 

[JohnPW]

Hello,

Charles, have you ever used Hock A2 cryogenic plane irons or the Veritas PM V11? I strongly suspect if you had, your sniffy posts would stop. Both are truly remarkable steels and since steel like good old W1 is no longer made and O1 seldom if ever hammer forged to give it that good old grain structure, we need advances in steel technology if our craft is to prevail. I first bought an A2 plane iron after using a particularly ornery wood that actually curled the edge of my plane iron after a couple of passes. The hock iron did not falter. I recently tried a PM blade out of curiosity and it is even better. I don't understand the resistance to progress here. I particularly like the Clifton plane irons, but it looks like they will not continue making them. Tools cannot be hammer forged without tremendous expense, which most users will not bear, so arguing that old tool steel is best is moot since you will not pay for its continued manufacture.

Mike.

There's a How It's Made video of chisels being hammer forged, and those were the very ordinary plastic handled socket type chisels. And Ashley Isles certainly hammer forge and I suspect others like Narex and Pfeil as well. I would guess whilst chisels with a bolster or socket are always hammer forged, the small American boutique makers have to makes chisels without a bolster because they cut the chisel from a solid bit of metal because, I've read on the forum, they don't have the equipment to hammer forge.

 

[G S Haydon]

I'm not and engineer https://www.youtube.com/watch?v=gittWRq2Sjk is that called a die press? I think that video a good example of mass made quality tools.

 

[Derek Cohen (Perth Oz)]

Well, I have a Hock iron in a Record 4 1/2 but alas it's O1. It's fine. It does stay sharper a little longer. It's harder steel, slightly more work to grind and slightly more work to hone. All in all it's about a wash, time-wise. Never have tried the frozen stuff.

I had a Lie Nielsen plane (a scrub plane) which of course came with A2 and I hated the cutter. I replaced the plane with a vintage Stanley. Love it. Love the plain high carbon steel, love the way it cuts, love the way it hones. I love it. It leaves nothing to be desired IMO. You can practically carve with that little pipper.

I demo'd a PM-VII chisel and while it was beautifully made I don't see what all the fuss is about. It's probably better as a plane iron. It totally did not rock my world.

So yep, I've used all these steels. I even had a mortise chisel in D2 which I loathed. I couldn't put an edge on that ba$tard with SiC sandpaper. Horrific. It never formed a wire edge just this little hump I kept chasing front to back that would never come off. Came dull and stayed dull.

Yeah Charles, that makes you an expert on these steels! :lol:

Regards from Perth

Derek

 

[Corneel]

In handtool use there is always the balance between long wearing and easy sharpening. Because we are no machines, we can't continue to work forever, so sharpening more often isn't as bad as it sounds. The pleasure of having a fresh edge is for some people more important then a longer lasting edge. It's very subjective of course.

D2 probably is a poor choice for handtools. It has too much chrome, is not very tough, is hard to sharpen. O1 is perfectly allright if you don't mind the shorter edgelife. A2 has a micro cracking problem, which can be dealt with a steeper bevel, it lasts a little longer then O1 but is a little harder to sharpen too. On PMV the jury is still out.

I don't know if hamer forging really makes a lot of difference for O1. I've never seen the Cliftons rising to the top in any of the many tool tests (amateur tests of course). The Japanese manage to make some remarkable stuff, they manage a great balance between the very hard cutting edge and the soft backing.

 

[rafezetter]

Well up to the last few posts (steady boys - and you too Derek) this has been a fascinating read. I'm not surprised the Japanese seem to have the edge (sorry) on making super sharp, but also long lasting, tools. After all they started making swords hundreds of years before anyone else and to a standard that even relatively modern antique versions (the last 150-200 years or so) sometimes command 6 figures sums. For them the art is in the making, not the making of profit from that making, and it's worth noting there isn't a traditionally trained sushi chef in the world that would deign to use a western knife.

The info on microcracking and how to reduce it's manifestation is something I'll definitely try to remember as I've have to grind out a few nicks recently and have a load of old chisels that I bought I've not yet got around to sorting out. For the regrinds, I have (and would have continued) to just put them in my sharpening jig and sat it on a belt sander until the nicked edge was just gone.

It's also made me resolute to go over a few of my very new chisels, which have only been taken to my level of sharp edge (still paper slicing razor - or so I thought...) once or twice and hardly used, again. Prolly the reground plane blades too.

I'll be honest and say I've not noticed a difference, but then my sense for this sort of thing is still extremely new.

Someone might be able to answer a simple question though which may advance that sense... recently I was working some reclaimed cedar and in the box joint bases should a ChrVa tool steel chisel be sharp enough to slice out the endgrain instead of mostly tearing? (my sharpening regime finishes with 5000 grit wet,dry and a micro back bevel; good enough to slice paper).

If it should have sliced - what do ppl recommend to get that final zing for this sort of very soft wood as I have a fair bit of it to work.

 

[woodbrains]

There's a How It's Made video of chisels being hammer forged, and those were the very ordinary plastic handled socket type chisels. And Ashley Isles certainly hammer forge and I suspect others like Narex and Pfeil as well. I would guess whilst chisels with a bolster or socket are always hammer forged, the small American boutique makers have to makes chisels without a bolster because they cut the chisel from a solid bit of metal because, I've read on the forum, they don't have the equipment to hammer forge.

Hello,

Drop forging is different. The only new tools available, forged by hammering, are Japanese tools, (blacksmith made) and only the more expensive of those (very!). The small grain structure, even alloyant distribution and even grain alignment found in tools produced by repeted heating and hammering. This yeilds steel with the best balance of toughness, hardness and fine sharpenabiliy. For example, the Stanley 5001 chisels (very good tools in the day) are made from a steel ( EN31, I believe) which is drop forged. The same steel could be used by Japanese blacksmiths, and hammered repeatedly and will be improved enough to enable it to be harder and tougher and take a finer edge, but exactly the same steel. (OK forge welded to a softer back too) For better or worse, metallurlogical developments try to impart these characteristics in steels without having to resort to expensive hot working the steels. There are always compromises though and some are more successful than others. But I do think cryogenically treating the steels does give noticeable benefits over what we have been used to in recent years and PM V11 is really good. On abrasive materials it is peerless for edge holding and can be got truly sharp, with my water stones. Can't say if it is easy on oilstones, I've not tried, though I suspect might take a while longer. The problem is, I suspect, there is such little interest in hand tool development over industrial cutting equipment, I don't suppose there is much effort put into the development of new steels specifically for planes and chisels, so steels will just be picked from stocks made for other purposes, to the closest approximations of what is needed. I think PM. V11 is a good approximation, though.

Mike.

Edit,

Clifton made fine plane irons by hammer forging, but seem to have abandoned the method in favour of cryogenically treated steel. I'd like to compare the results one day as their old irons were fine.

 

[Jacob]

In handtool use there is always the balance between long wearing and easy sharpening. Because we are no machines, we can't continue to work forever, so sharpening more often isn't as bad as it sounds. The pleasure of having a fresh edge is for some people more important then a longer lasting edge. It's very subjective of course.
.....

Well yes if you have a simple sharpening regime (freehand on one or two oilstones) it makes a nice little break and you have freshly sharpened edges a lot of the time. A bit like sharpening a pencil and about as difficult.
I think the obsessing about steel quality has a lot to do with the problems due to the pointless fashion for thick blades and complicated modern sharpening regimes.

 

[Derek Cohen (Perth Oz)]

I am not a metallurgist, however I do have a fair amount of experience both using and testing aspects of the various steels in a woodworking context. There are a few accounts of these on my website (under Tool Reviews) for anyone with the interest. I have in use all of the time O1, A2, M2, M4, D2, CPM-3V, and PM-V11. My amateur experience ...

First and foremost, before one can make a pronouncement on any of these steels, it is important to get them sharp. This means using appropriate honing media. For some of these steels there is no free lunch. For example, when I first tried it, I thought CPM-3V just not capable of a sharp edge. I was using the wrong media. When I switched to diamond paste it came alive! Anyone here attempting to hone M4 or D2 with oilstones may as well be using a blunt nail for an edge. This is an extreme example, but just to get my point across. Now this is not a discussion of sharpening, the merits of various stones, or whether various steels are good or bad because they require something different. It is simply to point out that one cannot pronounce on a steel until you can get it sharp.

The second point I want to make is that all the steels have pros and cons, and you need to decide where your priority lies - some excel at ease of sharpening with simple media (such as an oilstone or a natural waterstone), but then struggle to hold an edge with anything more abrasive than pine. Some excel in abrasion resistance for planing, and others for impact resistance for chiseling.

I suspect that a key factor to edge durability is a combination of how fine the grain is, how hard the steel becomes, and how elastic it is. For planing, one may want more abrasion resistance (more chromium?) and for chopping one wants more impact resistance/elasticity. I'm surmising here - feel free to throw this out the window, but give evidence if you do so.

I have come across an interesting graph showing the correlation of these features ..

This shows how the steels may increase their elasticity with chromium and moly.

Japanese laminated steels are essentially O1 steel but they do well, and I suspect that this is because the cutting layer is very hard and that this only survives as a result of a soft, elastic backing. They seem to do well both in edge holding when planing and when chopping in hard, abrasive woods (if my experience and tests count).

Steels such as D2, which have large carbide grains and many find hard to sharpen, appear to have more elasticity, and this be why they do so well in (Ray Iles) mortice chisels. I have a D2 blade in a jack plane, and it excels here as well. Perhaps like the RI, it is better at chopping. And yet high end planemaker Philip Marcou (in New Zealand) considers D2 a wonderful steel for smoothers. He argues that it needs to be left softer than most do.

O1 steel is really poor at edge retention when chopping end grain and planing abrasive face grain compared to all the steels above. A2 is about double its ability, and look where it stands in relation to other steels ...

PMV-V11? I think that it is excellent for planing abrasive woods, but especially good for chopping with chisels. It would make a good alternative to D2 in mortice chisels, and runs close to laminated Japanese steels for paring chisels.

Regards from Perth

Derek

 

[G S Haydon]

Hi Grayorm

Does better steel get sharper? For a politician style response I'd say you need something to be the right steel for the job. For second fix carpentry, joinery and most furniture making a set of chisels from a supermarket has the right steel for the job, as do the 5001's you have. The edges last long enough, more than long enough and they sharpen readily. The added benefit of choosing chisels like I've mentioned is you have much more £ left in your pocket for timber, hardware or even a few more essential tools! The sharpening media to suit those steels is also easier on the pocket. If all you do is work highly abrasive timer you might need to look at alternatives.

I don't have O1, A2, M2, M4, D2, CPM-3V, and PM-V11 in constant use in my set of tools. Heaven knows I like to experiment and see how other things work but I think most people interested in making something would be better served by practicing paring, chopping, sharpening and sawing to a line using a set of chisels from a supermarket and an appropriate saw rather than worrying about how long and edge might last.

Just my 2d's worth

 

[Bluekingfisher]

I would suspect your Fatmax chisels do not retain a sharp as long as some other chisels because that is the way they have been set up by Stanley? They are of course carpenters chisels and most likely subject to all manner of rough and aggressive treatmen. They probably will not need to be razor sharp, as one would expect from a furniture grade chisel.

I would have thought carpenters don't spend time honing a blade on a stone, more likely to grind an edge on a belt sander or such. So perhaps the manufacturer knows this and formulates the steel accordingly.

A classic case of the right tool for the job?

David

 

[Jacob]

I.... I was using the wrong media. When I switched to diamond paste it came alive! ....... It is simply to point out that one cannot pronounce on a steel until you can get it sharp. .......

I hereby pronounce that any steel which you can't easily get sharp, is useless!
If you have to buy special kit it might make more sense to dump the tool instead and get your money back on ebay.

Sharpening is an essential and continuous part of the process just like sharpening a pencil if you were drawing. It needs to be easy. The tool needs to be usable.

 

[Trafalgar]

"The second point I want to make is that all the steels have pros and cons, and you need to decide where your priority lies - some excel at ease of sharpening with simple media (such as an oilstone or a natural waterstone), but then struggle to hold an edge with anything more abrasive than pine."

This is absurd on its face -- 'struggle to hold an edge in anything more abrasive than pine.' Pure hyperbole and exaggeration, probably on even the worst chisels somebody could lay hands on, much less decent brands.

 

[Trafalgar]

I would suspect your Fatmax chisels do not retain a sharp as long as some other chisels because that is the way they have been set up by Stanley? They are of course carpenters chisels and most likely subject to all manner of rough and aggressive treatmen. They probably will not need to be razor sharp, as one would expect from a furniture grade chisel.

I would have thought carpenters don't spend time honing a blade on a stone, more likely to grind an edge on a belt sander or such. So perhaps the manufacturer knows this and formulates the steel accordingly.

A classic case of the right tool for the job?

David

It's better if a carpenter's chisel fail by rolling rather than by fracturing. They are made this way intentionally. They need to be honed at a higher angle because they are most often used to chop framing lumber and not pare fine joints. In the U.S this might mean chopping Southern Yellow Pine whose rings can seem as hard as petrified wood.

 

[Corneel]

Here is some data from the steel makers.

First to compare O1 to A2. O1 is Arne. A2 is Rigor:



Then a very interesting article from Crucible. Here you can compare A2, D2 and stuff like CPM 3V

http://www.crucibleservice.com/eselector/general/generalpart1.html

As you can see. A2 has a little more abrassion resistance then O1, but is less tough. D2 is slightly more abrassion resistant then A2 but is very much less tough. And a steel like CPM-3V is better overall, but it is harder to grind (takes longer) and you need diamonds for honing.

 

[Cheshirechappie]

I'm not and engineer https://www.youtube.com/watch?v=gittWRq2Sjk is that called a die press? I think that video a good example of mass made quality tools.

Hi Graham!

Yes, I think that is a hydraulic forging press fitted with suitable dies. The dies have to be made individually for whatever you're forging, so Narex will have a top and bottom die for each size of chisel they make. Sometimes, the dies have two or even three 'stages' (say, a roughing stage, a press to final shape stage, and a final stage trimming off the 'flash' - the waste squeezed outround the edge of the chisel blank). Conequently, Narex will have a lot of capital tied up in expensive one-off tooling and a large press. The rest of the video shows some pretty specialist grinding and heat-treatment kit, too; they've clearly invested a lot, and intend to manufacture and sell in bulk. I do agree that it's a good example of mass production engineering; they may well have had to do quite a bit of trial-and-error fiddling ('development' in engineer-speak) to get things just right, though.

There are several other ways to make a chisel. Obviously, there's hand-hammer and anvil, which would be appropriate for one-offs or very short runs. Then there's multiple-strike forging under a small power hammer (usually a spring hammer, though Henry Taylor use a Blacker hammer for some of their carving tools) fitted with dies made for the job. Ashley Iles still use the spring hammer method for drawing out their chisel blades, though I think they use a hydraulic press for the tang and bolster end. Then there's drop forging, which uses similar dies to those in the hydraulic press, but with the top die attached to a large weight (up to 10 tons for some applications, probably a ton or so for chisels) which is hoisted to a suitable height and then allowed to drop under gravity, thus doing with one bang what a spring hammer would need maybe a couple of hundred to achieve.

All those methods are quite capable of producing a decent chisel blank. Some people claim that some steels respond better to one method rather than the others - to be honest, I do wonder if there's a bit of personal preference involved. The method selected by an edge tool maker is probably more about capital investment in dies and plant against expected production volume as it is about the finer points of individual tool steels. Most edge-tool steels respond quite well to forging, but you do have to be a bit careful about forging temperatures with some of them.

 

[Cheshirechappie]

I don't have O1, A2, M2, M4, D2, CPM-3V, and PM-V11 in constant use in my set of tools. Heaven knows I like to experiment and see how other things work but I think most people interested in making something would be better served by practicing paring, chopping, sharpening and sawing to a line using a set of chisels from a supermarket and an appropriate saw rather than worrying about how long and edge might last.

Just my 2d's worth

I'm rather inclined to agree. A lot of the 'this steel is better than that steel' debates sound a bit like motor-sport enthusiasts arguing the finer points of Ferraris and Maseratis. Such differences could matter in motor-sport racing, but for most of us needing a car for the daily commute, the weekly shop and an occasional trip to visit Aunt Mabel then the bog-standard Ford, whilst not as glamorous, will do the job perfectly adequately and not cost as much to buy or service. That said, the motor-racing wallahs are perfectly entitled to their sport, too, of course.

 

[Trafalgar]

Another strategy might be to invest four figures in sharpening kit then go on a quest for steels that would have one rarely use it.

 

[Cheshirechappie]

Well up to the last few posts (steady boys - and you too Derek) this has been a fascinating read. I'm not surprised the Japanese seem to have the edge (sorry) on making super sharp, but also long lasting, tools. After all they started making swords hundreds of years before anyone else and to a standard that even relatively modern antique versions (the last 150-200 years or so) sometimes command 6 figures sums. For them the art is in the making, not the making of profit from that making, and it's worth noting there isn't a traditionally trained sushi chef in the world that would deign to use a western knife.

The info on microcracking and how to reduce it's manifestation is something I'll definitely try to remember as I've have to grind out a few nicks recently and have a load of old chisels that I bought I've not yet got around to sorting out. For the regrinds, I have (and would have continued) to just put them in my sharpening jig and sat it on a belt sander until the nicked edge was just gone.

It's also made me resolute to go over a few of my very new chisels, which have only been taken to my level of sharp edge (still paper slicing razor - or so I thought...) once or twice and hardly used, again. Prolly the reground plane blades too.

I'll be honest and say I've not noticed a difference, but then my sense for this sort of thing is still extremely new.

Someone might be able to answer a simple question though which may advance that sense... recently I was working some reclaimed cedar and in the box joint bases should a ChrVa tool steel chisel be sharp enough to slice out the endgrain instead of mostly tearing? (my sharpening regime finishes with 5000 grit wet,dry and a micro back bevel; good enough to slice paper).

If it should have sliced - what do ppl recommend to get that final zing for this sort of very soft wood as I have a fair bit of it to work.

When grinding out a nick, you've no option but to grind past the edge. I'm not sure I'd go as far as to say that micro-cracking WILL occur, just that if you end up with an edge that seems a bit brittle, it might have happened. However, just carry on using and re-honing, and if it has happened, the chances are that intervals between rehonings will increase as the damage is honed away.

On the softwood problem - yes, I know exactly what you mean! In some respects, soft, open-grained woods can be a harder challenge than harder, denser ones; they tend to crush rather than cut. They really demand sharper edges than some harder woods. If possible, using a slicing rather than stabbing cut can help, thogh that's not always possible - cleaning up dovetails, for example. Another thing some have tried is a lower bevel angle, but regrinding bevels for different woods can shorten chisels faster than most of us would like! Some people keep a few paring chisels with a lower bevel angle than their chopping chisels, and use those for situations like this - not with a mallet though! Probably the best solution is keeping the edge dead sharp, and touching up on the polishing stone more often than you usually would, and being a bit pragmatic about surfaces that will be hidden after assembly - work from both sides so that surfaces are cut clean to the marked line, and don't obcess too much about the middle, hidden, bit.