Does better steel get sharper?

[Graham Orm]

I have a set of Stanley Fatmax chisels that I use for work. They do a job, but loose their edge quickly. I bought some Stanley 5001's from Ebay. These are reputedly made from ball bearing grade steel.....whatever that is? All the hoo har seems to be right. I've been using them for work for a week and they deffinitely stay sharp longer.
However.
They also seem to get sharper when sharpening. I've gone through the back flattening process with the Fatmax's but they would just never get to thet paper slicing razor edge that the 5001's do or my Narex bench set do. I've bought another four from Ebay and will now have 9 or ten in my box. (I always like to have duplicates, so I can grab another rather than sharpening when one goes off). Happy days and cheap as chips.

 

[Racers]

Better steel will get sharper, its grain size is smaller and they are probably harder, it all helps to get a really good edge.

Pete

 

[jimmy_s]

I was thinking the same.

I have some footprint chisels that I use regularly, they take a good edge but recently I bought a couple of Japanese chisels and was surprised at just how sharp these were after sharpening.

I have some old Ward and Mathieson chisels that I keep for more careful work, out of curiosity I checked the Jap ones against these as well; the Japanese ones definitely felt markedly sharper.

 

[Cheshirechappie]

Maybe a qustion for the American forums - they love this sort of debate.

There are very many grades of steel. One reference book we had in the design office listed about 4000 commercially available grades. All of them could be sharpened to an edge, though some will hold that edge better than others, and some would take a better edge. A piece of angle-iron can be made into a chisel, and will take quite a sharp edge - but not for long.

I'm not sure there are any 'absolute' answers (despite all the debate). If there was one grade of steel that took an amazing edge and held it for ever under almost any working circumstances, eveybody would be using it exclusively; there isn't, hence the variety.

'Ball bearing steel' (En31, 535A99, or SAE52100 to the Americans) is quite close to being a 1% straight carbon steel. It has a little bit of chromium - about 1% to 1.5% - in it to help final hardness and depth of hardening, a tiny bit of silicon and a bit of manganese. It's been around for many years, and has, I gather, been used for edge tools from time to time. The fact that it's a simple alloy very close to 1% straight carbon steel may be part of the explaination for it's good edge-taking and holding compared to some of slightly more complex alloys; other alloys might do even better.

There again, what constitutes 'a good edge' and 'good edge-holding' is a bit subjective. Different working circumstaces, and all that. Some want super-sharp, and will touch-up the edge often. Others want long-lasting, and will take a slightly less sharp edge or slightly higher bevel angle. All down to personal opinion, really.

There are not many 'bad' steels out there. The odd example of poor heat-treatment or overheating during grinding show up from time to time, but most toolmakers use steel adequate for the purpose. It's entirely a matter of personal opinion where the line is drawn between 'good enough' and 'not quite good enough'.

Though no doubt somebody will be along with a different opinion!

 

[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.

 

[MMUK]

I can see this turning into a full on sharpening debate :lol:

 

[Jacob]

Harder steel will keep an edge longer but is harder to sharpen. So it's a trade off.
Perhaps the logical best solution is the laminated blade - hard but thin edge steel on the face and a soft back for speedy sharpening.

 

[Graham Orm]

Thanks for the input guys. It seems I'm right in that good steel does take a better edge. I thought it was some short fall in my technique that the Fatmax's wouldn't become insanely sharp.

 

[Graham Orm]

Harder steel will keep an edge longer but is harder to sharpen. So it's a trade off.
Perhaps the logical best solution is the laminated blade - hard but thin edge steel on the face and a soft back for speedy sharpening.

the question Jacob is does good steel get sharper? It seems there is a reasoning that it does.

 

[Jacob]

Harder steel will keep an edge longer but is harder to sharpen. So it's a trade off.
Perhaps the logical best solution is the laminated blade - hard but thin edge steel on the face and a soft back for speedy sharpening.

the question Jacob is does good steel get sharper? It seems there is a reasoning that it does.

Depends on what you mean by "good steel".
I suppose hard steel must get sharper but I don't know. But that's not necessarily the same as good steel if it takes too long to sharpen.
You can get an incredibly sharp edge on glass but it'll only cut soft stuff (such as your skin) so that's no good either!

It comes down to compromises over the practicalities of actually using the tool on an actual job.

PS Stanley 8001 - did you mean Stanley 5001? These are harder than the blue handled ones, can be made very sharp, probably keep an edge longer, but take longer to sharpen.

 

[Phil Pascoe]

The reason your FatMax doesn't hold its edge for long is that they are designed as site chisels - if you use chisels made of a better, harder steel they would chip too easily. It better to try to use a tool that's slightly blunt than one with a gert chip out of the edge.

 

[Cheshirechappie]

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.

 

[Jacob]

The reason your FatMax doesn't hold its edge for long is that they are designed as site chisels - if you use chisels made of a better, harder steel they would chip too easily. It better to try to use a tool that's slightly blunt than one with a gert chip out of the edge.

Well yes. I tried to use Stanley 5001s on site but they get chipped very quickly so I keep them for cleaner work where more precision needed. They can be honed to 25º which'd probably be too fine for the Fatmaxs. Horses for courses.

 

[bugbear]

I have a set of Stanley Fatmax chisels that I use for work. They do a job, but loose their edge quickly. I bought some Stanley 8001's from Ebay. These are reputedly made from ball bearing grade steel.....whatever that is? All the hoo har seems to be right. I've been using them for work for a week and they deffinitely stay sharp longer.
However.
They also seem to get sharper when sharpening. I've gone through the back flattening process with the Fatmax's but they would just never get to thet paper slicing razor edge that the 5001's do or my Narex bench set do. I've bought another four from Ebay and will now have 9 or ten in my box. (I always like to have duplicates, so I can grab another rather than sharpening when one goes off). Happy days and cheap as chips.

It's obvious that a more abrasion resistant steel will be ground less by a given abrasive.

This means that (in practise) an abrasion resistant steel will act as if the abrasive were finer, and finer abrasives give sharper edges.

Assuming harder steels are also more abrasion resistant, this would nicely explain the effect you're seeing.

This theory could be tested, by putting both types of steel though a sequence of grits that ended in a grit deemed to be "too fine", thus negating the postulated effect. If both chisels can be got to equal sharpness this way, the theory would be pretty well proven.

The "which chisel is best" discussion is much broader, and I'm staying out of it.

BugBear

 

[Beau]

"Does better steel get sharper?" Depends what you call better.

I have never studied the science of metals but can share my experience of various blades from over the years.

Best edge I have ever had is from an Expensive Japanese chisel. It's relatively easy to sharpen as well but I rarely use it for the simple reason the edge is too brittle.

I have tried expensive plane irons from Victor and Holty and both have their issues and neither takes a better edge than my original cheap Record blade but they both hold a duller edge for a long time.

It's all a compromise between sharpness, brittlness, longevaty and ease of sharpening. For me Oire Nomi chiesels offer the best compramise but if on site an old set of Marples does well enough. Can't comment on the Stanleys as never used them.

 

[Trafalgar]

'Ball bearing steel' (En31, 535A99, or SAE52100 to the Americans) is quite close to being a 1% straight carbon steel. It has a little bit of chromium - about 1% to 1.5% - in it to help final hardness and depth of hardening, a tiny bit of silicon and a bit of manganese. It's been around for many years, and has, I gather, been used for edge tools from time to time. The fact that it's a simple alloy very close to 1% straight carbon steel may be part of the explaination for it's good edge-taking and holding compared to some of slightly more complex alloys; other alloys might do even better.

Basically Japanese 'blue steel.'

Check out the table found here (scroll down to approx. mid-page): http://www.astbearings.com/bearing-materials.html

 

[Graham Orm]

Harder steel will keep an edge longer but is harder to sharpen. So it's a trade off.
Perhaps the logical best solution is the laminated blade - hard but thin edge steel on the face and a soft back for speedy sharpening.

the question Jacob is does good steel get sharper? It seems there is a reasoning that it does.

Depends on what you mean by "good steel".
I suppose hard steel must get sharper but I don't know. But that's not necessarily the same as good steel if it takes too long to sharpen.
You can get an incredibly sharp edge on glass but it'll only cut soft stuff (such as your skin) so that's no good either!

It comes down to compromises over the practicalities of actually using the tool on an actual job.

PS Stanley 8001 - did you mean Stanley 5001? These are harder than the blue handled ones, can be made very sharp, probably keep an edge longer, but take longer to sharpen.

Yes my mistake. Black handle yellow ring very early 5001's black handle white ring later 5001's with nickel finish. Blue handle 5002's (unknown quantity).

 

[Corneel]

Toolsteel is a fascinating subject. I am far from an expert, just read a bunch of websites...

How a toolsteel behaves depends on at least two factors, hardness and chemical composition. How the steel was produced and with how much skill it was hardened and tempered plays a very important role too.

Rarely was a toolsteel designed especially for handtool woodworking. We want a very sharp edge and we also want it to be very easy to sharpen and hone too. Our demands on durability are laughable when you compare it to steels used in the industry. But those two important factors for us, compromise the durability. Durability comes in two forms, wear resistance and toughness. These contradict each other, a hard wearing toolsteel is usually less tough. Making the steel harder increases the wear resistance but decreases its toughness, it becomes brittle.

O1 is very simpe steel, it has about 1% carbon which makes it hardenable. It also contains a few other elements in small fractions which help it's hardening ability. W1, the more old fashioned tool steel, is even simpler, contains not much more then steel and carbon. It is not as easy to harden, likes to crack and warp. These steels have very fine grain and are easy to sharpen. They have a good compromise between sharpenability, wear resistance and toughness.

A2 contains about 1% carbon, 5% chrome, 1% molybdenum and up to 0.5% vanadium. The chromium, molybdenum and vanadium form carbides. These are very hard, much harder then the steel and carbon. But they tend to cluster together in much larger crystals when the steel starts to solidfy during manufacturing. These large crystals tend to create cracks in the steel. So while they increase the wear resistance, they are not so good for the toughness. They also make the steel harder to sharpen. D2 conatins even more chromium and vanadium making it even more wear resistance but less tough. In other words, better for plane irons then for chisels.

These are conventional toolsteels. They are mixed in a large furnace and then poored into ingots where they can solidify. After that they will be rolled flatter which compressed the steel too. The formation of the large carbides is a problem, especally vanadium is a problem. It is very good for increased wear resistance, but is also really likes to create very large crystals. Large fractions of vanadium are not possible in a conventional toolsteel. But the industry really wanted steels with more vanadium. That's why powdered steels were invented. The steel is melted, then atomised in a kind of spray. They cool very quickly so the crystals don't have the time to grow. Then the powder is compressed under very high pressure and heat to create a solid steel again. The result is a fine grained toolsteel. The steel makers can now add much larger quantities of vanadium. For example CPM-3V, CPM-10V, CPM-15V with increasing amounts of vanadium. That makes a very wear resistant tool steel which is still pretty tough. No magic here either, increasing wear resistance among the PM steels still reduces toughness. And while these steels are relatively easy to sharpen, they are still a lot harder to sharpen then O1.

Which brings us to sharpening technology. You need a sharpening medium comatible with the steel. While oilstones are perfect for O1 and W1, they are not so great for steel with a lot of carbides. You need something which abrades much more agressively, like modern waterstones or even diamonds.

Recently a "new" toolsteel was introduced by LV, PMV-11. They claim that it is a powdered toolsteel, has better wear resistance and toughness then O1 or A2 while it is still easy to sharpen. Of course they didn't invent it themselves, steel making is a separate industry. They most probably used one of the many special knife steels. There are plenty of these around. It is a stainless steel (easy to determine) and because it is still easy to sharpen it can't contain very much vandium. There are not many powdered steels with small quantities of vanadium. This steel still needs to prove itself in the handtool world. First reports are encouraging, but that was the case when A2 was introduced too.

 

[Trafalgar]

Yep, people practically soiled themselves over A2 (and to some extent D2 and CPM process steel) and then the same crowd offered a repeat performance when PM-V11 came out. Any more "new" tool steels hit the woodworking tool market I'm going to buy stock in an adult diaper manufacturing company.

Good that you put "new" in quotes in your last paragraph.

 

[woodbrains]

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.