A2 or O1 Steel?

[Clark Harbaugh]

Just a quick question - I recently read a post on here that explained the difference and when to use one vs the other in hand planes, but now I can't find it. I seem to recall one is tougher to sharpen but will hold the edge longer, so my logic tells me this would be good in jack planes, vs. the other is easier to hone and is typically better in smoothers and joiners. I may have that mixed up a bit...

Can one of you help clarify this? Thanks.

[James Taglienti]

If you use the search box at the top right of the screen you will find countless pages of data and debate regarding A2 and O1. More than anyone could ever care to read in entirety I am sure. Also any internet search on the subject will be very bountiful. I cant bear to talk about the two any more, but our endless dialog in the SMC archives should satisfy your every question! good luck!

[Ryan Baker]

The short answer is that A2 is slightly harder to sharpen and holds an edge longer. O1, in theory, can take a sharper edge, and is slightly softer. In the real world, it makes very little difference. You can easily sharpen either on any stone you will have around. My first choice if available would be PMV11, especially for something like a jack plane, because of the better edge life. After that, I choose A2 for all of my plane blades where I have the choice (the ones I make are O1).

[Jim Koepke]

Your best answer may be found by buying one of each and then finding where one or the other works best for you.

jtk

[Zach Dillinger]

My first choice is vintage cast steel, followed by O1. A2 is a very distant third.

[Charlie Stanford]

My first choice is vintage cast steel, followed by O1. A2 is a very distant third.

Well said.

[Derek Cohen]

Just a quick question - I recently read a post on here that explained the difference and when to use one vs the other in hand planes, but now I can't find it. I seem to recall one is tougher to sharpen but will hold the edge longer, so my logic tells me this would be good in jack planes, vs. the other is easier to hone and is typically better in smoothers and joiners. I may have that mixed up a bit...

Can one of you help clarify this? Thanks.

Hi Clark

I would say that you have this correct. O1 and A2 fail differently. A2 will hold an edge longer as long as it is honed above 30 degrees, and some will find that they do not get as sharp an edge on A2 (which is incorrect, but more than I have time to answer now). The fact that it holds an edge longer than O1 makes it the preferred option in situations where durability is the priority. O1 tends to fail sooner, but (as long as it has been tempered correctly) will fail more gently. This, and its apparent greater ease in sharpening, makes it the preferred option for smoothers. Having said his, I have used A2 in smoothers for many years and enjoyed the extended life it offers. Watch the surfaces of the wood and the edge of the blade and you won't go wrong.

Regards from Ottawa

Derek

[David Weaver]

If you are sharpening with oilstones, stick with O1 and vintage carbon steel.

If you're sharpening with anything else (waterstones, honing films, etc), you'll probably be indifferent about the steel used. More is made of the differences than there is substance in using the tools, almost universally if you see someone who doesn't like A2 for planes, it's an oilstone user.

There definitely is something attractive to sticking to carbon steels and using oilstones and dumping all of the other stuff that's got more alloying than O1.

(Just don't buy a bunch of A2 stuff and hone it at 25 degrees. It makes no sense at anything less than 30, it's just harder to sharpen than carbon steel and will last less well below 30, planing or chiseling).

[Chris Griggs]

If you are sharpening with oilstones, stick with O1 and vintage carbon steel.

If you're sharpening with anything else (waterstones, honing films, etc), you'll probably be indifferent about the steel used. More is made of the differences than there is substance in using the tools, almost universally if you see someone who doesn't like A2 for planes, it's an oilstone user.

There definitely is something attractive to sticking to carbon steels and using oilstones and dumping all of the other stuff that's got more alloying than O1.

(Just don't buy a bunch of A2 stuff and hone it at 25 degrees. It makes no sense at anything less than 30, it's just harder to sharpen than carbon steel and will last less well below 30, planing or chiseling).

Pretty much exactly how I feel.

[Zach Dillinger]

almost universally if you see someone who doesn't like A2 for planes, it's an oilstone user.



I resemble that remark...

[george wilson]

If you intend to harden and temper your own plane irons,stick with 01. A2 requires to be wrapped in an airtight hi temp. stainless steel foil envelope.

Keep in mind that it is ASSUMED that all the steels mentioned herein were PROPERLY hardened and tempered in ideal temperatures(which may or may not always be the case unless correctly calibrated pyrometers are used.) I have one on my furnace.

As some have said,01 will take a keener edge than A2,but will not hold it as long.

Here's the lineup: W1 was the steel used in the old days. It is a very simple steel,consisting of just iron and carbon. It will take the keenest edge of the other steels,but will not stay sharp as long as it has no additives for wear resistance. It is also the most treacherous to harden. It must be hardened in water(hence W1),or brine(better).It can warp more easily than other steels. It will get harder than other steels(I've seen it reach 67 Rockwell C),but it has no mechanical strength at that hardness,and the edge can crumble right off. Therefore,it needs to be tempered at about 400º to get down to 60 Rockwell C (RC),or a bit lower in my opinion. Since in the old days,little was known about chemistry,and natural mined ores VARY in chemistry,antique W1 steels vary in composition,and might have tungsten or other alloys,unknown at the time,present. There were even natural deposits is stainless steel available in certain places. Some Scottish all steel flintlock pistols were made of it. They were highly prized in the 18th.C. and earlier. We have an 18th.C. fireplace set in Williamsburg made of natural stainless steel. Eric Sloane mentions finding a bright wood gouge buried in a stone fence he was repairing,in one of his books.

01 steel is the next simplest steel,having a few additives to increase wear resistance and deep hardening. Thus,it needs to be cooled more slowly or it can crack. Thus the use of an oil as a quenching medium. It will stay sharper longer than W1,but will not take quite as keen an edge. Everything is a trade off: You get more or less keenness for more or less durability.

A2 is more complex,having more alloys,like chrome,to cause it to harden very rapidly. It is cooled in still air,or in fanned air. Still will do. I like it the best for making mating punches and dies for my wife's jewelry business because it warps hardly at all,and changes dimension hardly at all,important when a shaped punch must fit exactly into a hole. It gets less sharp than 01. Make no mistake,it still gets plenty sharp for woodworking and is a great metal for tools. It holds an edge longest of the 3.

The final proof of keenness for me was when I had to skive pillow soft chrome tanned Sea Ray leather on the suede side.A2 just would not cut the feathery softness of the fluffy suede. I was able to skive it with a block plane that had an original LN blade that was made of (I have been advised) W1. LN had told me that their first blades were 01,but I'm not sure that was correct. I'd have to grind it and look at the type sparks it makes to verify what steel it is(called a spark test). It's not that important to me. It is enough to know it will get the sharpest.

So,the final test is not if the blade will cut wood. For me,it is if the edge will get keen enough to cut the softest,most yielding material,like the super soft suede referred to. It was said that the test of the finest Damascus scimitar was to cut a thin silk cloth tossed in the air. Some say to cut silk allowed to slide down the blade,but who knows where legend gets factual ! I'd vote for tossed in the air.

These are the results I have found from hardening hundreds of various types of blades and tools since the 1960's.

I'm not yet sure where LV's PM VII powdered steel falls in this. I got a VERY sharp edge when I first sharpened my PM blade for my NX 60 LV block plane. Must try it on the suede!!

Not that any of you would try to use it,but I can tell you that really highly alloyed steel like D2(contains 12% chrome),WILL NOT sharpen on a stone less hard than the Spyderco ceramic ones!! At least not the way I hardened and tempered my few knives made from it.

[Charlie Stanford]

I resemble that remark...

Remember when D2 was all the rage? Wonder what happened.

[David Weaver]

Remember when D2 was all the rage? Wonder what happened.

It's getting combined with two new powder metal steels. R2 and PMC3PO.

Guaranteed to help any woodworking mog go plaid.

[David Weaver]

I resemble that remark...

I knew it! You're one of them!! (oh wait..I already knew it).

[Mike Cogswell]

Aren't the Ray Iles mortise chisels made from D2?

[David Weaver]

Yes, the mortise chisels are still available, as are the blades made from D2. Like everything else, there's a burst of publicity when it comes out and then not as much, but it's all still made.

All of the discussions have gone toward PM V11 lately, anyway.

[Gary Hodgin]

Aren't the Ray Iles mortise chisels made from D2?

Yes, I don't have any but Tools For Woodworking says they're D2.

[george wilson]

MY EXPERIENCES with D2 ONLY reflect how I have been hardening and tempering the steel myself,and there are SEVERAL different ways of doing it. Therefore,I did not mean to say that ALL D2 steel acts the same way. I have had a lot of experience with W1,01,and A2,but not a whole lot with D2. So,take what I said of D2 with a grain of salt.

I decided to delete my D2 comments because they could be misleading.

[Charlie Stanford]

Aren't the Ray Iles mortise chisels made from D2?

They are. I owned one for two days before I sent it back. Couldn't put a scratch on it with Scary Sharp.

[george wilson]

Like I said,my D2 experiences are that they need VERY HARD STONES,like Spydercos. The 12% chrome and other alloys make a very tough,wear resistant steel. Originally intended for blades for shearing steel.

[Clark Harbaugh]

Guys,
I appreciate the feedback. I thought I had it straight and appreciate the confirmation. I use (currently) king water stones, so it sound like A2 would be no more problem to sharpen. I will probably do what Jim K suggested and get one or two of each to see what I like. The plan is to build 4 plains (block, smoother, jack, and joiner) using the Lee Valley irons for wood planes. I built one a couple of weeks ago using scrap wood and the existing irons I had from a cheap Groz # 4 I had, just to see how well it would work for me. Funny thing, I always thought my poor plane performance was due to my perceived lack of sharpening skills. After putting the iron in my woodie, I realized it was the the plane itself. I've tuned and re-tuned the #4 but just cant get it right. Now it doesn't matter, as it took less time to build the wood plane than all of the time I have spent trying to tune the Groz :).

[John Coloccia]

Guys,
I appreciate the feedback. I thought I had it straight and appreciate the confirmation. I use (currently) king water stones, so it sound like A2 would be no more problem to sharpen. I will probably do what Jim K suggested and get one or two of each to see what I like. The plan is to build 4 plains (block, smoother, jack, and joiner) using the Lee Valley irons for wood planes. I built one a couple of weeks ago using scrap wood and the existing irons I had from a cheap Groz # 4 I had, just to see how well it would work for me. Funny thing, I always thought my poor plane performance was due to my perceived lack of sharpening skills. After putting the iron in my woodie, I realized it was the the plane itself. I've tuned and re-tuned the #4 but just cant get it right. Now it doesn't matter, as it took less time to build the wood plane than all of the time I have spent trying to tune the Groz :).

I owned a Groz for about 10 minutes. Took one look, boxed it up and returned it.

[David Weaver]

I've not found D2 that bad to maintain. I haven't gotten anything made in D2 other than mortise chisels, I wouldn't want to get a 2 1/2 inch wide iron that is out of flat, but it's stayed polished and sharp well on the two types of stones I've used, a pair of shapton pros and a kitayama (one of those inexpensive softer finishers) 8k stone.

It's got nothing on the muji plane irons that I have in terms of being harder to abrade.

[Clark Harbaugh]

I owned a Groz for about 10 minutes. Took one look, boxed it up and returned it.

Yep. It was given to me or else I would have returned it. I fusses with it for a couple of years with mediocre results. Glad to know its not just me.

[Charlie Stanford]

But why David? The buzz was all about D2. Then it was A2, or was it A2 before it was D2? And now it's PM stuff but O1 keeps dragging people back in.

Does any of this stuff strike you as ridiculous? I mean, how much time and money can somebody spend chasing all these new steels around?

[John Coloccia]

But why David? The buzz was all about D2. Then it was A2, or was it A2 before it was D2? And now it's PM stuff but O1 keeps dragging people back in.

Does any of this stuff strike you as ridiculous? I mean, how much time and money can somebody spend chasing all these new steels around?

There are advantages and disadvantages to the different steals, Charlie. It's not about chasing anything. It's about making an informed decision. People can do good work with ANY steal, but given that we have different metals with different properties, what possible reason could you have for not matching the steal to the job? Maybe we should all go back to bronze? I don't get it.

[george wilson]

Matching steel to the job is what it is all about,especially in the tool and die industry. When a complex die set costing hundreds of thousands is made,it needs to not warp in hardening,and need as many pieces to be pinched out as possible between re grinds. Using different steels to make the SAME die set,you can go from 5000 cycles to 250,000 cycles between re grinding(which shortens the punches and dies).

My wife punches many thousands of pieces of polycarbonate and paper in the dies I have made her. Some have lasted nearly 20 years(glad she's not punching steel!). I chose to make them from A2 because it is more stable in heat treating(less than .0001" swelling in hardening,W1 swells so bad it may not fit the die),and A2 has longer life than 01. I could use D2,but it is difficult to machine or otherwise make the complex shapes. I can't use HSS because I haven't the means to heat treat it. That's an example of matching the steel to the job,in my small application. I am older than she is,and I need those die sets to last beyond me.

The amount of swelling or distortion varies with the size of the piece of metal you are working with. For our dies,usually 3/4" wide or often less(1 1/2" was the biggest I made for her),.0001" was held by the A2. Warping was negligible.

LN went to A2 blades because they had so much loss due to warping with the 01 or W1 they were using. They told me 01,someone else said W1. I'm wondering if they really make their blades,or if they are farmed out to a proper heat treater who makes them.

[David Weaver]

But why David? The buzz was all about D2. Then it was A2, or was it A2 before it was D2? And now it's PM stuff but O1 keeps dragging people back in.

Does any of this stuff strike you as ridiculous? I mean, how much time and money can somebody spend chasing all these new steels around?

You can avoid spending any of it. Like anything else. I don't know why you would worry about it if it's not your money.

[george wilson]

To Charlie: Not that much money to try a few different plane blades,compared to millions that companies can spend on more complex research about steels. By now,steel choices are pretty well nailed down by now,except perhaps for the new PM tech..

[Charlie Stanford]

There are advantages and disadvantages to the different steals, Charlie. It's not about chasing anything. It's about making an informed decision. People can do good work with ANY steal, but given that we have different metals with different properties, what possible reason could you have for not matching the steal to the job? Maybe we should all go back to bronze? I don't get it.

Just referring to the gushing about each one being the be-all and end-all. Then nothing.

Maybe I'm the lone idiot (should have written "loan" because that's what I would need) who doesn't have chisels and plane irons in A2, D2, Japanese white steel, blue steel, and super steel (??), PM-VII, O1, vintage crucible, vintage laminated (eastern and western), W1.... am I missing any? Seems like all the cool kids on the block have a selection of all of these. At least they write about them as if they had first hand experience. Mind boggling. I'm not sure I would characterize it as "matching the steel to the job." The material being operated on hasn't changed. Perhaps you are just being your charitable self.

Good on you.

[David Weaver]

If it bothered me as much as it bothers you, I wouldn't read about it. That would be a really simple solution.

[John Coloccia]

Personally, I feel like an idiot for giving him an actual, serious response. I'm pretty much done with the consistent condescension accompanied with no real contribution. I should know better than to feed the trolls.

[Sean Hughto]

Charles is more of a curmudgeon* than a troll. He has his points. He certainly respects quality woodworking and knows how to do the work.

*
http://www.concentric.net/~marlowe/curdef.shtml

[John Coloccia]

Charles is more of a curmudgeon* than a troll. He has his points. He certainly respects quality woodworking and knows how to do the work.

*
http://www.concentric.net/~marlowe/curdef.shtml

I'm a curmudgeon. I don't like much of anything...LOL. What's Charlie's point? It's not like you can choose to NOT choose a steel. They're out there. You HAVE to choose something. Maybe Charlie's point is we shouldn't have a conversation about it on a forum? Seriously. It's gotten old.

[David Weaver]

Charles is more of a curmudgeon* than a troll. He has his points. He certainly respects quality woodworking and knows how to do the work.

*
http://www.concentric.net/~marlowe/curdef.shtml

That's far too kind.

[Sean Hughto]

I'll let Charles speak for himself as to what he means. That said, speaking for myself - I was once an eager hobbiest anxious to learn the secret bests. The best sharpening method, the best plane, the best steel, and on and on. It's like chasing one's own tail. You think those things matter a lot. Then you work wood a bit and see that they really are not all that important compared to things that really matter like design, practice, perseverence, and simple love for creating. After a certain point, it's somewhat amusing/bemusing to watch folks obsess over the minutiae. All decent steels cut wood well.

[george wilson]

An example of selecting the steel in the realm of planes would be when I want an edge to last,especially on abrasive woods like ebony,I choose A2 so I don't have to sharpen as often. But,I mentioned in post #11 where I had to use a block plane to skive down the suede side of some very soft,yielding suede on a sea ray skin. About the softest suede I have dealt with. I needed to skive the leather down to the thickness of paper.. W1 worked,A2 wouldn't get sharp enough. Longevity of the edge wasn't as important as just being able to get the blade sharp enough to shave that fluff down! I need to try my PM blade from LV on it!

I have indeed tried everything Charlie mentioned except Japanese planes(have tried their chisels). I just can't get interested in them.

[glenn bradley]

I'm not a purest and find A2 to give me a good, workable, lasting edge at the bench. As stated by others, a finer edge can be achieved with other steels and I have these for marking knives, spoke shaves and several chisels. the "best" steel for the job is the one that works "best" for you.

[Charlie Stanford]

That's far too kind.

I'm still wondering if I left any steels off my list....:)

Trust me, if I thought a steel that lasted fifteen more minutes (if even that long) between honings was the difference between the dam finally breaking for me in a flood of production and creativity wild horses couldn't keep me from buying every bit I could lay my hands on. But it's not. Won't be. And never will be. No way. No how.

So, one more mortise gets cut before the chisel needs honing. Whooptee freakin' doo! Say it with me again folks, whooptee freakin' doo! (can I get a whooptee $hit?) I mean, really. Ain't I Robert Townsend now? I'd need a smoke break anyway. Of all the crap that slows me down in the shop (lack of talent mostly) honing surely must be the last item on the list. Without a doubt it is.

I can actually see where honing makes some break out in a sweat. They can't decide how to do it. They're literally years into the craft and still have two or three full 'systems' hanging around the shop (or remnants thereof or more) and they are paralyzed with doubt about how to pick one and proceed to master it. It's just pure lunacy. It really is. So, when it's time hone there is the doubt, the fumbling and futzing rather than the practically automatic, nearly mindless task it ought to be. It's sad. It's practically become an end in itself. Weekends and evenings lost to honing, twiddling, and faffing. And then they start buying tools made of "new" steel which does have an impact on the media used so they drag out (or repurchase) a 'system' they tried a couple of years ago or buy some new stuff out of Japan and the cycle repeats itself. Over and over.

[David Weaver]

I doubt any of what you described occurs in many shops where someone has a few years of experience.

The buying and trying part might be true, but it exists solely of means and not need.

[Charlie Stanford]

I doubt any of what you described occurs in many shops where someone has a few years of experience.

The buying and trying part might be true, but it exists solely of means and not need.

Certainly a possibility. I guess any sort of forum post boils down to a matter of whether or not a shoe fits. That's the nature of the beast.

[george wilson]

I can't disagree,Charlie. The endless discussions on sharpening here seem to prove it!!:)

[Jason Coen]

I'll let Charles speak for himself as to what he means. That said, speaking for myself - I was once an eager hobbiest anxious to learn the secret bests. The best sharpening method, the best plane, the best steel, and on and on. It's like chasing one's own tail. You think those things matter a lot. Then you work wood a bit and see that they really are not all that important compared to things that really matter like design, practice, perseverence, and simple love for creating. After a certain point, it's somewhat amusing/bemusing to watch folks obsess over the minutiae. All decent steels cut wood well.

This process occurs in all hobbies, and because of that, I'd say it's part of what makes a new hobby so initially engrossing. New golfers obsess over the latest and greatest composite shafts or dimple patterns on balls, new high-power shooters obsess over the newest land and groove configuration or marginally faster wildcat caliber, new tennis players obsess over string tension, yadda yadda yadda.

In whatever hobby, it all comes back to trying to buy a way to improvement. If one stays with it long enough, we sooner or later realize it's the Indian and not the arrow and that building skill is far more important towards the ultimate outcome than is buying widgets. For most people it seems pretty tough to get to that place without a certain amount of experimentation. I guess we all have a need to see or try things for ourselves to see what works best in our individual situation before we really believe what those with more experience try and tell us.

[Jack Curtis]

I understand what you're saying about the obsessive worry about sharpening, even agree with it; but there are new people taking up the sport every day, and they haven't a clue. The rags don't tell them enough, so to whom are they to turn? Well, a bunch of old coots each of whom sharpens with a different system that they've used every day for 40 years and works for them. So how about a break for these new/newish woodworker?

[Jason Coen]

I understand what you're saying about the obsessive worry about sharpening, even agree with it; but there are new people taking up the sport every day, and they haven't a clue. The rags don't tell them enough, so to whom are they to turn? Well, a bunch of old coots each of whom sharpens with a different system that they've used every day for 40 years and works for them. So how about a break for these new/newish woodworker?

Well said. Except for the "old" part - I may be a coot, and I may sound like a grumpy old man, but I was born in the '80s. :D

[Zach Dillinger]

Well said. Except for the "old" part - I may be a coot, and I may sound like a grumpy old man, but I was born in the '80s. :D

I've had people read my posts and assume I'd fit in on a movie set with Walter Mathau and Jack Lemmon. Surprises some to learn that I'm not yet 30 :)So I understand what you're saying!

[James Taglienti]

Ive got a Benchmade pocket knife in D2 that sharpens on a norton india. It must not be hardened as much as woodworking tools. It can get a razor edge, though, and hold it about as long as... well.. any non stainless knife ive ever had i suppose.

[Jason Coen]

Ive got a Benchmade pocket knife in D2 that sharpens on a norton india. It must not be hardened as much as woodworking tools. It can get a razor edge, though, and hold it about as long as... well.. any non stainless knife ive ever had i suppose.

Benchmade knives typically test a point or two lower than their stated hardness. Depending on the knife, this can be anywhere from 58-62. The only knife steel I like better than the D2 that Benchmade uses is the Elmax steel in my ZT 0561. It's as easy to sharpen as D2, and is holding an edge better than the couple of M4 Spyderco's that I have.