Replacement Plane Irons.

[bugbear]

Early Stanley propaganda said the advantage of the thin blade was less or no grinding. It said nothing about performance!

Indeed - one of Baileys's patents contains the following telling phrase "...whilst I can avail myself of the economy of thin steel for the plane-irons" (my emphasis).

BugBear

 

[Jacob]

....samurai blade ......

Sharpening should be very easy as the soft steel is easily
abraded and there is only a very thin layer of very hard steel.
I think Jacob you used this one right?

Yes it's OK and sharpens easily. Probably keeps an edge longer but not significantly. I keep trying these things but they never are quite as wonderful as they say!

.....
Jacob, did I misread you owning a BU smoother/jack, which you reserve for more demanding woods? Thick iron with a firm bed support right to the cutting edge; I think you are secretly agreeing with me.......
Mike.

I thought I should try one. Its the LV la smoother. It cuts really well. When my other planes start tearing out I use this one, just now and then, for finishing.
Only need the one though - I don't see the point of converting them all to smoothers!

....
The idea of moving the frog backwards so the iron rest on the plane body is flawed in that the wider mouth will cause more tearout, negatin any benefit in doing so. The bevel down blade probably won't get much more, if any, support in doing so, anyway. ...
Mike.

If you look closely at a normal Bailey plane you will see that 2 to 3 mm of the back of the blade is supported on the back of the mouth - if the frog is set back precisely (plus a gnats more). Best with a single 30º bevel, next best rounded, worst hollow ground with micro bevel; each step leaves more blade unsupported and more prone to chatter. I think closing the mouth on a normal plane is a bit of a myth, but having it spot on makes a huge difference.

...

You forget to mention one pretty important part: the blade clamp. That one presses down the thin iron and thin capiron on the frog. When you have the screw tight enough, there is no problem to clamp it absolutely flat on the frog. The curve in the capiron helps to get the pressure exactly where you want it, just behind the edge. It's a smart design. ....

Agree

....With a two-piece cap-iron the force from the lever-cap on to the bottom piece of the cap-iron (the deflector) is transferred to the cutting edge and to a point about 1 inch above the cutting edge (where the deflector meets the main part of the cap-iron) holding this whole area flat against the frog. The Stanley-Bailey bent cap-iron simply does not do this well.

Or at least that's my theory...

Cheers, Vann.

You are probably right, but it does it well enough!

If you check, I think you will find that all chipbreakers (except Stay Set) bend the blade. This causes two point contact with the frog. Top and bottom of the slope. The lever cap does not flatten the middle of the blade, to touch the frog surface.

Doesn't matter as long as it is firmly nipped in the edge area and supported by the back of the mouth

 

[Gerard Scanlan]

Thank you for all the fine tuning advice. As with all things the longer you spend doing something and the more critically you look at the more you learn. It is then really terrific reading about the fine points of adjustment and being able to put them to immediate use. It also amazes me how quickly you accept an improvement as the norm and probably explains why woodworkers are always on the look out for that everlasting razor-sharp edge that can be rehoned in seconds when it eventually dulls.

I am a little puzzled by the recent convex honing debate that crept in here too. Paul Sellers recently relaunched this, yet James Krenov advocated the opposite - concave with micro-bevel. In my ignorance I now believe it is whatever you can do fast as after all we want to be making sawdust, not swarf, all day.

 

[Jacob]

...
I am a little puzzled by the recent convex honing debate that crept in here too. Paul Sellers recently relaunched this, yet James Krenov advocated the opposite - concave with micro-bevel. In my ignorance I now believe it is whatever you can do fast as after all we want to be making sawdust, not swarf, all day.

You have to make up your own mind and not take anything for granted - particularly if it came from Krenov!

Hollow ground with a micro bevel is a poor way to sharpen as it leaves you with the most fragile edge compared to the other options. But it's easy for beginners (if they have a grindstone of course) so probably a good simple way to get started. Old Jim was very much the amateur, as he often said himself.

 

[woodbrains]

.....
Jacob, did I misread you owning a BU smoother/jack, which you reserve for more demanding woods? Thick iron with a firm bed support right to the cutting edge; I think you are secretly agreeing with me.......
Mike.

I thought I should try one. Its the LV la smoother. It cuts really well. When my other planes start tearing out I use this one, just now and then, for finishing.
Only need the one though - I don't see the point of converting them all to smoothers!

....
The idea of moving the frog backwards so the iron rest on the plane body is flawed in that the wider mouth will cause more tearout, negatin any benefit in doing so. The bevel down blade probably won't get much more, if any, support in doing so, anyway. ...
Mike.

If you look closely at a normal Bailey plane you will see that 2 to 3 mm of the back of the blade is supported on the back of the mouth - if the frog is set back precisely (plus a gnats more). Best with a single 30º bevel, next best rounded, worst hollow ground with micro bevel; each step leaves more blade unsupported and more prone to chatter. I think closing the mouth on a normal plane is a bit of a myth, but having it spot on makes a huge difference.

Hi,

So are you saying the sole of the plane under thefrog should be a little forward of the frog ramp to contact the blade in the bevel!? Cheeses, how are you supposed to advance the blade. This would only work for one blade depth setting; you couldn't advance it to take a thicker cut and reducing the cut would lift the blade off the sole so the support was all on the frog as per usual. No. If you are strange enough to want to move the frog backwards, it should be level with the sole. However, you will get no advantage in doing this, because the sole portion of the ramp will be lost in the gap under the bevel and not add any support, unless you have want to take such an enormously thick shaving that the blade back could actually contact that part of the plane. No. all you are doing is gaping the mouth and it is by no means a myth that a finely set mouth prevents tearout. Planes without cap irons RELY on the principle that the downward pressure in front of the mouth prevents the shaving lifting ahead of the cut which is what tearout is. Cap irons mitigate the problem slightly, but not so much as you can have a mouth opening of the order you would need, to have the frog level with the rear mouth opening.

Regarding taking Krenov's advice with a pinch of salt: I spent 9 months with the guy; he was cantankerous and opinionated and sometimes rude but the most inspirational character you would like to meet and an authority on planes. It is unlikely that disagreeing with him on the finer points of planing would do you any favours. His little handmade wooden planes performed at least as well as any LN and degrees better than more standard fare. If thick irons, heavy cap irons and rock solid blade seating with a micro fine mouth did this for him, then it is churlish to question the point of it all. It works with the back up of solid evidence for Pete's sake. Removing even one of the fine details and the whole system falls apart. By calling himself amateur, he meant that he would not take professional expedients, but would always do the most appropriate thing that he thought correct. Don't confuse the true meaning of amateur, which means something done for the love of it, with not being an expert, which he most definately was. And if Mr Charlesworth says somthing works for a reason, then it would be just as churlish to disagree with him.

Regarding Samurai irons: too expensive these days to be a serious consideration. I got one about 14 years ago; they are thin, which would improve with a 2 piece cap iron--but why bother when you can get something thicker for no more money. The surface grinding on the back was as coarse as I have seen and 'cause the steel is so hard, a bear to polish out. Also, I'm fairly sure that they should only be ground and honed with just one flat bevel, so the softer lamination gives maximum support to the hard lamination, as per a regular Japanese iron. Those who favour secondary bevels might be losing some of the advantges of these blades. I don't much like them, but maybe I have a bad one.

Mike.

 

[Cheshirechappie]

Thanks to everyone who replied to my question about Bailey-type plane iron thicknesses. Seems they have varied a bit, but there's not much correlation between thickness and year of manufacture - between about 1.85mm and 2.4mm seems to be the range. For what it's worth, I measured my Cliffie iron, and it's a very consistent 2.94mm across the blade about 1/2" behind the cutting edge, so call it 3mm. Given that blade stiffness is proportional to the cube of blade thickness, that's a significant improvement, and experience from a number of people would seem to bear that out.

As to material, I've been doing a bit of rootling about in my old engineering textbooks, and thinking about the markings that Vann reported on his older irons - 'Crucible Cast Tungsten Steel', 'Tungsten Steel' and 'Tungsten Vanadium Steel'. The analysis of modern O1 steel is Carbon 0.85-1.00%, Silicon 0.40% max, Manganese 1.10-1.35%, Chromium 0.40-0.60%, Tungsten 0.40-0.60%, Vanadium 0.25% max, the balance Iron. An older reference gives about the same analysis without the Vanadium. It therefore seems entirely possible that (post-war) Stanley and Record irons are BS 4659 BO1 steel (that's what we generally call O1), the reference stamped on the blade may be just a bit of marketing 'polish', like a car manufacturer putting alloy wheels and go-faster stripes on a bog-standard hatchback. The pre-war situation is more confused, because British Standards didn't (generally)cover steel grades then.

Metallurgically, the addition of tungsten causes the formation of Tungsten Carbides with some of the carbon in solution, so improves hardness. Vanadium has a similar effect, and both slow grain growth during the hardening process, so should promote a finer-grained steel than a pure carbon steel. I'm speculating now - it may be debatable how pronounced this effect is, and how much it is negated by the tempering process to remove brittleness. I'm not sure that O1 (or 'Ground Flat Stock' as it's often sold) gives noticably higher hardnesses in practice than, say, Silver Steel, or the old plain carbon 'Cast Crucible Steel'.

(For anybody daft enough to want to research this further, instead of getting some wood shavings made, the main reference I used is 'Engineering Metallurgy' by Higgins, Volume 1, fifth edition, 1983.)

So the conclusion is the old and newer Bailey irons are basically O1 steel, or something very close to it. Thickness varies, but they are thinner, and therefore significantly less stiff, than modern Clifton/Isles/Hock irons. As others have pointed out above, stiffness can be improved by using a close-fit cap iron, and other measures like ensuring a firm, rock-free bedding against the frog will help too.

 

[Jacob]

...
So are you saying the sole of the plane under thefrog should be a little forward of the frog ramp to contact the blade in the bevel!? Only in the sense of being positively in line - with a bias towards being advanced rather than being behind Cheeses, how are you supposed to advance the blade.

No prob. If you slide the blade down the frog ideally there should just be a fleeting contact with the mouth as it goes past. A thou or something. Done by feel and sighting

.This would only work for one blade depth setting; you couldn't advance it to take a thicker cut and reducing the cut would lift the blade off the sole so the support was all on the frog as per usual. No. If you are strange enough to want to move the frog backwards, it should be level with the sole. However, you will get no advantage in doing this, because the sole portion of the ramp will be lost in the gap under the bevel and not add any support,

Wrong. Have a look at a plane. About time you did!

unless you have want to take such an enormously thick shaving that the blade back could actually contact that part of the plane. No. all you are doing is gaping the mouth and it is by no means a myth that a finely set mouth prevents tearout. Planes without cap irons RELY on the principle that the downward pressure in front of the mouth prevents the shaving lifting ahead of the cut which is what tearout is.

So they say but `I don't believe it

Cap irons mitigate the problem slightly, but not so much as you can have a mouth opening of the order you would need, to have the frog level with the rear mouth opening.

Regarding taking Krenov's advice with a pinch of salt: I spent 9 months with the guy; he was cantankerous and opinionated and sometimes rude but the most inspirational character you would like to meet and an authority on planes. It is unlikely that disagreeing with him on the finer points of planing would do you any favours. His little handmade wooden planes performed at least as well as any LN and degrees better than more standard fare. If thick irons, heavy cap irons and rock solid blade seating with a micro fine mouth did this for him, then it is churlish to question the point of it all.

Big if. Would like to see the evidence

It works with the back up of solid evidence for Pete's sake. Removing even one of the fine details and the whole system falls apart. By calling himself amateur, he meant that he would not take professional expedients, but would always do the most appropriate thing that he thought correct. Don't confuse the true meaning of amateur, which means something done for the love of it, with not being an expert, which he most definately was. And if Mr Charlesworth says somthing works for a reason, then it would be just as churlish to disagree with him.

They are normal people just like you and me and can get things wrong the same as we do. The "cult of expertise" is not good and is unconstructive. "Gurus" should have tomatoes thrown at them at regular intervals. If in doubt, stick two fingers up! Churlish of them if they think they are immune from disagreement.

 

[woodbrains]

Thanks to everyone who replied to my question about Bailey-type plane iron thicknesses. Seems they have varied a bit, but there's not much correlation between thickness and year of manufacture - between about 1.85mm and 2.4mm seems to be the range. For what it's worth, I measured my Cliffie iron, and it's a very consistent 2.94mm across the blade about 1/2" behind the cutting edge, so call it 3mm. Given that blade stiffness is proportional to the cube of blade thickness, that's a significant improvement, and experience from a number of people would seem to bear that out.

As to material, I've been doing a bit of rootling about in my old engineering textbooks, and thinking about the markings that Vann reported on his older irons - 'Crucible Cast Tungsten Steel', 'Tungsten Steel' and 'Tungsten Vanadium Steel'. The analysis of modern O1 steel is Carbon 0.85-1.00%, Silicon 0.40% max, Manganese 1.10-1.35%, Chromium 0.40-0.60%, Tungsten 0.40-0.60%, Vanadium 0.25% max, the balance Iron. An older reference gives about the same analysis without the Vanadium. It therefore seems entirely possible that (post-war) Stanley and Record irons are BS 4659 BO1 steel (that's what we generally call O1), the reference stamped on the blade may be just a bit of marketing 'polish', like a car manufacturer putting alloy wheels and go-faster stripes on a bog-standard hatchback. The pre-war situation is more confused, because British Standards didn't (generally)cover steel grades then.

Metallurgically, the addition of tungsten causes the formation of Tungsten Carbides with some of the carbon in solution, so improves hardness. Vanadium has a similar effect, and both slow grain growth during the hardening process, so should promote a finer-grained steel than a pure carbon steel. I'm speculating now - it may be debatable how pronounced this effect is, and how much it is negated by the tempering process to remove brittleness. I'm not sure that O1 (or 'Ground Flat Stock' as it's often sold) gives noticably higher hardnesses in practice than, say, Silver Steel, or the old plain carbon 'Cast Crucible Steel'.

(For anybody daft enough to want to research this further, instead of getting some wood shavings made, the main reference I used is 'Engineering Metallurgy' by Higgins, Volume 1, fifth edition, 1983.)

So the conclusion is the old and newer Bailey irons are basically O1 steel, or something very close to it. Thickness varies, but they are thinner, and therefore significantly less stiff, than modern Clifton/Isles/Hock irons. As others have pointed out above, stiffness can be improved by using a close-fit cap iron, and other measures like ensuring a firm, rock-free bedding against the frog will help too.

Hi,

I think you are more or less correct, a few things I have read over the years bears this out, though I have not gone into metal science too deeply. You more or less re-itterate what I briefly said earlier. tungsten is added to improve grain structure that would normally be achieved in carbon steel by the hammering process. Removing the need for hammering is a cost cutting excercise which was my point. The blades were thin to save steel, they could be stamped out more easily whereas thicker irons probably would have had to be cut then edges ground. Thinner blade blanks would requre less energy to harden and temper, all economies, there is no advantage at all for the performance of the plane with thin irons, all manufacturing expedients.

However, as far as I see it adding tungsten causes some other issues. The grain structure might be improved over stock, untreted carbon steel, but the carbides actually tend to have an affinity to clump together in the steel and are not as uniformly distributed as might be liked. So there are in effect strands of carbide throughout the steel which I think causes non-uniform hardness and brittleness throughout the steel which is partly why the performance is patchy. Vanadium also forms carbides, but really is only beneficial in HSS and only make sharpening plane irons problematic. They may hold an edge longer than carbon steel but it wont be as sharp to begin with. Evidently, any more than about 1% carbon in steel has no benefit in hardness and most importantly toughness and the excess carbon is only there to be available to form carbides, otherwise it will just remain as graphite. I might be wrong, but I think re-heating and hammering over and over helps include more carbon in the metal matrix, so a slightly higher percentage of carbon is achieved, whereas carbide forming alloyants have to be added to acheive the same in the standard blades. I'm not saying that these are not sophisticated alloys, they are and probably could only be acheived with ultra high tech apperatus available today, but they don't do what we need for a fine blade, which is toughness above all. The fascination with high Rockwell scale numbers is only useful to a point. Rc 68 or something found in a Japanese iron for example, is only part of the story. The repeated hammering and folding of the metal by the blacksmith imparts toughness and therefore better edge retention than would be acheived by a similarly hard alloy steel stamped from a sheet. The edge of the latter would simply crumble under pressure as it will be brittle.

Mike.

 

[woodbrains]

They are normal people just like you and me and can get things wrong the same as we do. The "cult of expertise" is not good and is unconstructive. "Gurus" should have tomatoes thrown at them at regular intervals. If in doubt, stick two fingers up! Churlish of them if they think they are immune from disagreement.

Sorry Mr Charlesworth, I didn't want to put you in the line of fire, someone is having a tantrum.

Mike.

 

[Jacob]

They are normal people just like you and me and can get things wrong the same as we do. The "cult of expertise" is not good and is unconstructive. "Gurus" should have tomatoes thrown at them at regular intervals. If in doubt, stick two fingers up! Churlish of them if they think they are immune from disagreement.

Sorry Mr Charlesworth, I didn't want to put you in the line of fire, someone is having a tantrum.

Mike.

Not a tantrum. Just defending the right we all have to disagree with anybody and everybody!
It's not churlish at all.

Regarding taking Krenov's advice with a pinch of salt: I spent 9 months with the guy; he was cantankerous and opinionated and sometimes rude but the most inspirational character you would like to meet and an authority on planes. It is unlikely that disagreeing with him on the finer points of planing would do you any favours. His little handmade wooden planes performed at least as well as any LN and degrees better than more standard fare. If thick irons, heavy cap irons and rock solid blade seating with a micro fine mouth did this for him, then it is churlish to question the point of it all.

I take it you have replaced all your planes with little knobbly Krenov jobs? If not, why not?
I'm sure he was inspirational - in fact we all know that as he obviously inspired many. But then you have to move on.

 

[Corneel]

Regarding the sole supporting the blade instead of the frog.

I meassured the thickness of the sole in my 1920's Stanley #7, and in a UK made Stanley #4. It's only 2.5mm thick. It's much thicker at he other ends of the plane, but just there where the frog comes down, they ground the sole to this 2.5 mm.

So the length of steel at 45 degrees of the sole is 2.5 / sin(45) = 3.5 mm.

The iron is 2.2 mm thick.
When we calculate the length of the bevel when the primary is 25 degrees, we find 2.2 / sin(25) = 5.2 mm.
When we calculate the length of the bevel when the primary is 30 degrees, we find 2.2 / sin(30) = 4.4 mm.

Conclusion: The sole has no role in supprting the iron

Regarding clamping a thin iron to the frog:
I see absolutely no light between the clamp downed iron assembly and the frog while using the thin irons in a good old vintage Stanley
I do see a little tiny bit of light when using the thicker Ray Iles iron in a much newer Stanley.
I don't wittness real chatter while using my Stanley planes, like I once saw in a wooden plane with a wobbly bed for the blade. That was bad, in the middle of a stroke on a hard piece of wood I got these rather deep lines of a chattering iron. You can see that sometimes happen with a scraper blade too.

My conclusion: I think flexing of the iron on a well bedded Stanley frog isn't really much of an issue. The issue is much more how well the frog is fabricated.

 

[Corneel]

Wait a second, I made all kind of stupid mistakes in that calculation. I'll do a retry.

 

[Jacob]

Conclusion: The sole has no role in supprting the iron

Wrong. 0/10 must try harder! :lol:

Wait a second, I made all kind of stupid mistakes in that calculation. I'll do a retry.

Instead of doing that why not take out the frog, put the blade in situ as for a fine cut - and have a look at it! :shock:

 

[Corneel]

Here is a quick picture in Paint. It shows that the bevel length is only part of the solution.

The length x = bevellength * sin (20) = 5.2 * sin 20 = 1.77.

So the new conclusion: Yes the sole plays a role in supporting a thin iron, even at a low grinding angle of 25 degrees.

BTW, a thick iron has a much longer bevel. The Ray Iles iron is 2.9 mm thick, so it has a bevel length of 6.86mm. In that case the value x becomes 2.3mm. The support of the sole is almost non existant in this case.

 

[Corneel]

Yes I know what you mean Jacob. I tried but maybe it was too dark in the shop. I didn't see anything down there.

 

[Jacob]

Here is a quick picture in Paint. It shows that the bevel length is only part of the solution.

The length x = bevellength * sin (20) = 5.2 * sin 20 = 1.77.

So the new conclusion: Yes the sole plays a role in supporting a thin iron, even at a low grinding angle of 25 degrees.

BTW, a thick iron has a much longer bevel. The Ray Iles iron is 2.9 mm thick, so it has a bevel length of 6.86mm. In that case the value x becomes 2.3mm. The support of the sole is almost non existant in this case.

Instead of doing that why not take out the frog, put the blade in situ as for a fine cut - and have a look at it, Measure it too whilst you are at it. :roll:

 

[Corneel]

It's freezing in the shop and nice and warm here behind the computer. :ho2

 

[woodbrains]

Hi,

So now the sole isn't slightly forward of the frog to provide contact in the bevel. I swear you just make it up as you go along. It is highly unlikely that this portion of the rear mouth opening is even in the same plane as the frog ramp anyway, unless you take the trouble of some fettling with a file, etc. and let's face it you haven't done that, either.

A 3mm thick replacement is nearly 3 1/2 times more rigid than a standard one so doesn't require any dubious frog setting so you can close up the mouth like you should to prevent tearout without fear of chatter. Couple this with a 2 piece cap iron which doesn't curve the blade when you nip up the cap screw and you have better frog contact and even more rigidity. Can't see the downside nor any reasonable argument against.

Mike.

 

[Richard T]

Dear Corneel,

If you substituted the iron in your diagram with one with a rounded bevel, the distance at "X" would be shorter and Jacob would be very happy ... so don't! :-$

 

[woodbrains]

Dear Corneel,

If you substituted the iron in your diagram with one with a rounded bevel, the distance at "X" would be shorter and Jacob would be very happy ... so don't! :-$

No, He 'rounds them under', so X would be bigger wouldn't it?