Observation about sharpenability - nomi

edge durability

Jack Dover

I don't know if you were reading here when I did a plane durability test - the HSS irons from china in clean wood do run about 60% further than a good O1 iron

I have watched your video about planes and remember that HSS iron from China and how you had taken translucent shavings with it and a glassy surface. That's when I've started questioning "HSS and alloyed steels can't get sharp", since my ultimate sharpness test is the quality of surface an edge produces.

Durability wise I'm ok with not getting all potential mileage out of a single plane sharpening. My average shop session is just a couple of hours a day, rarely a full day, so there's at most two or three sharpenings on any given day. I could save more time by not messing with a phone in a shop than by eliminating one sharpening session.

I'm more concerned with chisels edge folding soon after a sharpening. The assumption was my chisels are too soft hence the idea of a HSS set, but reading through this thread I'm not so sure anymore.

Planing vs chiseling

Jack Dover

That too is slowly dawning on me. My planes perform way better than chisels even though they're about the same in terms of quality. And then I have realized they're subject to totally different working conditions - I don't generally chop with a plane blade. So maybe it's an operator issue after all.

Re: Planing vs chiseling

Bill Tindall, E.Tn.

Not really an "operator error", just different forces acting on the edge. If all you ever did with a chisel was "split" wood the edge would last like a plane place splitting off shavings.

Re: A2 and carbon steel (to PM-vII)

Bruce McCrory

One of the last blurbs I read from Sauer was him adopting LV PM-vII blades, including his brand on the tool. Don't know anything about A2.

I think a classic Stanley or Millers Falls person would find my religious devotion to new manufacture outrageous. However, I have no guilt for being a clutz when fixing a rust bucket; or, trying to. If a luxury tool buyer can't handle a critique of his vanity trip, then he's not looking at his relationship with the tool correctly.

To me...

David Weaver

abrasion resistance isn't really that important. I like edge stability, which comes from a nice combination of toughness and hardness.

There are 50 other things that can be done to get more work done between sharpening sessions and I start to have some disdain for really abrasion resistant steels when I find that I almost completed the sharpening process on them.

Or the few that have poor edge stability because they're just defective.

You don't understand  HSS steel

Bill Tindall, E.Tn.

HSS is steel whose composition enables it to retain properties at high temperature. Period. No other property in implied. Given that this attribute is of no value in a chisel there is no reason to seek out any woodworking tool on the basis of it being high speed steel.

It could happen that some HSS has other properties that might make it a candidate for this or that woodworking tool. CPM 3V for example retains toughness at high hardness, and also happens to be a HSS. My experience with M2 suggests it is a lousy steel for chisels. Bottom line, zero correlation of the HSS and optimum properties for a chisel or what ever because we never use our tools at red heat like when milling metal.

Re: HSS chisels

Winston

I wasn't aware that Iyoroi made HSS chisels. I believe the ones I made were made by Koyama, but I don't know for sure. I also believe that when Stu was running his Tools from Japan store, he called them semi-HSS chisels.

I definitely would not want to sharpen them in the traditional Japanese way, with a flat bevel. Because they're HSS it's possible to take the chisel to a grinder without worrying about messing up the temper -- although I still don't grind them all the way to the edge, and I'm still careful about heat. I figure there's probably some reason that Stu called them semi-HSS, and it's better to be safe than sorry. With a hollow grind and a small flat bevel, it's not too difficult to sharpen them on Shapton Pro stones.

I have a couple of the green Chinese HSS plane blades that David has talked about before. That thing is in a completely different category. The Shaptons barely touch that steel. I recently spent a few minutes trying to sharpen it on a Shapton 1000 and barely made any progress. It was incredibly slow. But then I moved to a 1000 grit diamond plate, and that handled it just fine. I wouldn't be surprised if the diamond plate was 10 times as fast as the Shapton on this blade.

Those blades also didn't come with flat backs, and I had to resort to using a belt sander to take down the high spots on the back. This was when I was experimenting with putting a slight hollow on the backs of plane blades, so I wasn't concerned about getting the back perfectly flat -- only the edge and areas near the sides need to be flat, and the middle part of the blade is slightly convex.

Back to chisels... I don't know of any western chisels that are as hard as these HSS chisels. I have some low-end Japanese chisels (non-HSS) that have pretty hard steel, but I stopped using a while ago because they tended to chip. But that was before I started using a buffing wheel for sharpening. I wonder if those chisels with the unicorn profile would hold up well for difficult tasks like cutting mortises in oak.

Hard vs abrasion resistant

Bill Tindall, E.Tn.

When you use the word "hard" do you mean abrasion resistant? These terms correlate with a carbon steel. They don't when alloying elements are added that make carbides harder than iron carbide. Also they don't when powder metallurgy is used to manufacture the steel.

David sent me a Chinese plane blade to analyze. It had similar composition to M2 but was significantly deficient in alloying elements compared to M2. Is that what they call "semi"?

Many true high speed steels are alloyed with Tungsten to achieve performance at red heat when cutting metal. As the power tool users know, Tungsten makes very hard carbides. One of these steels at a Rockwell hardness of 62 will be vastly more abrasion resistant than a carbon steel at Rc 62. M2 at Rc 62 will be vastly more abrasion resistant than a carbon steel at Rc 62.

Both to winston and bill

David Weaver

I believe we found that in some cases, alloying elements in that iron were 25% shy of M2, but it made up for it in hardness (about65/66 on average for three strikes at the edge, and consistent in the strikes) vs. its claimed hardness (61) in the listing.

For planing, I think the combination of hardness and lacking in elements made it better. It probably has better edge stability than cast M2 (presuming they cast the non PM stuff in batches).

I have chisels made of the same steel. No clue how hard they are, but they sharpen on natural stones, just not quickly.

What they lack is edge stability just a little, but in toughness overall for chiseling, they are beyond typical chisels. They're cheaply made stamped bits stuffed into a handle (and the short tang and style with the handle gives up). They're high speed steel, though (both claimed by the listing and I ground one until it was red and used it after it cooled - still full hardness).

Now, onto the chisels that winston is talking about - I believe they are a material that Iyoroi lists as yxr7. I don't know what it is - it's a PM that may not have great hot hardness, or maybe it does. We won't challenge hot hardness the way metal workers do, even grinding. If anyone did, they'd burn their fingers on a regular basis by accident when going to sharpen after grinding. Those are laminated.

Then there are the types branded as "semi-hss" that are solid steel (I still have one of those to use when I make something where I'd trim or scrape metal and wood at a joint). I'm sure that both are technically less tough than something like A2 is on a chart from an industrial test, but they will tolerate use on metal which most carbon steel will not tolerate (and definitely not A2). The reason I keep one is because i learned the hard way that most carbon steel won't tolerate scraping brass.

These are the kinds of things that confuse me with some of the industrial tests. Some very tough materials that work well metal on metal lose their fine edge quickly, but tolerate trimming brass by hand. The funatzu or whatever it is that stu was selling fit in that group. They work a long time, but if you're used to a really fine edge, they kind of never have the same feel. I think there are too many carbides. You can sharpen them to hanging hair level, but i believe a bit of the edge leaves in use right away (just as I often tell the story of coaching a "professional razor" honer to hone one of the S#V steels in a custom razor - they can be sharpened to good shaving sharpness. you can't strop them, though, as even the strop will separate some of the carbides from a fine edge. They can actually shave fine if you like a brisk edge that hasn't been smoothed by a strop, but the only way to maintain them is to continuously refresh them in micro diamonds.

Just another example of edge stability vs. potential sharpness, but far detached from anything we use on a regular basis (far more and larger carbides than something like A2). Potential sharpness is the same for everything if you don't deflect the edge - it depends only on hardness as far as I can tell - the harder a steel is, the smaller the possible apex will be.

In regard to Winston's comment about overhard japanese chisels (very common). I have two tests for practical use. a couple of minutes of paring, and the buffer. Chisels that pare well without developing any defects will be fine for malleting. With a fat unicorn, a chisel that's a little overhard may meet that standard. There's another level of overhard beyond that that I've seen, and that is inability to take an edge at all because either of the following two damage the edge:

* the pressure of sharpening itself

* when the first is marginally a problem, the buffer will actually chip bits off of the steel

The difference with white steel in exhibiting the above is probably only one or two points on the C scale. It's hard to try to make tools in the 65 hardness range without testing each one and never see this kind of behavior. I've seen it in really expensive tools made by really highly regarded blacksmiths. Those tools are so expensive that people are afraid to modify them, and they're basically unusable then.

Good toughness can still be had at levels of hardness that won't raise a burr on a washita stone - sometimes even at hardness levels where india stones are marginally effective (Too slow cutting). That level provides tools that are reasonably tough, but inappropriately hard to sharpen. I don't see any improvement in edge life over something that can be sharpened on india and only polished on washita (probably 65 hardness). These tools are completely unsharpenable on any japanese (natural) stone I've ever had (and I've kept a couple of the strongest cutters out of about 150 or 200 stones). In historical use, they'd have been tempered further or cast aside.

Marketing of HSS...

David Weaver

as i mentioned below, the HSS chisels are often sold with incomplete or incorrect information. Some of the muji tools were sold as "A2", some were described as M2 by other people, and I've seen explanation of japanese yXR7 alloy as "M2", "M4". "M42".

I don't think it's any of those. what's puzzling, though, is the ability of these steels to cut brass with only minimal damage when equivalent hardness high carbon steels (and softer) will chip out and experience catastrophic failure.

The japanese HSS chisels can be sold at spec as high as 68 hardness. I don't know what they're made of (same Yxr 7?). The funatzu chisel that stu sent me to look at tested 67 hardness. In the ad copy, the HSS chisels are described as appropriate for use where metal in wood may be encountered (construction) and designed to be fast to sharpen because they allow use of a high speed grinder.

https://www.330mate.com/product/1606

I showed this list to stu years ago - the prices are in yen/100. For our purposes, a dollar can be assumed as the appropriate price. This guy's name is fujibato - he's not that friendly sometimes, but he's cheap. His sale price is half of what tomohito iida charged for identical chisels, but I believe he doesn't stock anything - you order, he orders, eventually you get what you ordered but requesting information or expressing dissatisfaction is a bad idea (or may be ignored entirely).

I asked stu if these iyoroi chisels (xr7) are the same as the ones he was selling under a different brand, and he said "yes. I have no idea how they make them for that price". They're probably just more efficient making them. The material when you see the chisels is obviously prelaminated from hitachi. They're just cut to shape and finished in a machine, and a handle is stuck on them.

I know fujibato will sell for these prices at least sometimes as I had a set of chisels like the one in the picture from him. $600 for a set of ten plus a nice kiri box thrown in and free shipping to the US ("grain" style in that price list). Tomohito iida had them listed at the same time with a different handle wood for $1225 (the cost at retail for those handles vs. white oak would've been about +$100), which is more typical of the markup to sellers who specialize dealing with US and euro buyers or who sell from the US.

No clue if the high speed steel chisels sold by TFWW are the same as the Xr7 chisels listed here, but they probably are (everyone working with the same stock coming from hitachi).

Fujibato's commentary claims they're 65 hardness, but they're probably harder. Google translate says something like "hard to sharpen even when new - use grinder and then sharpen by hand after grinder".

Going in circles a little here -because of the inaccuracy of information and the fact that these chisels are actually really tough (and probably not similar in any case to the softer M2 that's used in power tool blades), It's difficult to criticize folks thinking that high speed steel is tough.

Composition of YXR7

Wiley Horne

From Hitachi,

https://www.hitachi-metals.co.jp/e/yss/search/yxr7.html

Wiley

Re: Hard vs abrasion resistant

Winston

When I wrote "hard", I think I was using it in the same sense that you mean... With both the HSS and cheap chisels, I know they're hard because the edges don't fold easily.

The HSS chisels and the HSS plane blade take more work to sharpen than other blades that I have (especially so for the plane blade). From what you're saying, it sounds like that's due to additional abrasion resistance in those steels?

Funmatsu-Nezumi-Haisu

Derek Cohen (in Perth, Australia)

Stu sent this to me, calling it PM-HSS.

Incredible hardness and edge-holding when chopping, but you do not want to sharpen it!

Testing four steels: http://www.inthewoodshop.com/ToolReviews/FourChiselSteelsCompared.html

Regards from Perth

Derek

Re: Composition of YXR7

Bill Tindall, E.Tn.

I don't know about any other property but that load of alloying elements will make it one tough puppy to sharpen.

Re: Composition of YXR7

David Weaver

It's rubbery feeling on stones - slick. The high hardness (67 on mine) doesn't help to make them easier to sharpen, but I guess that's the intention.

If the tip is rolled (which is what I was doing pre-unicorn), though, they can be finished with an oilstone. Finished optimally? I'm sure not, but they can be made sharp enough to shave hair pretty easily.

like everything else I've come across, medium crystolon will cut it pretty easily at high hardness (the one I had was laminated, so maybe it wouldn't have been quite so easily if they were solid).

Stu told me that all of the laminated HSS from hitachi (at least what's in the tools) is effectively rolled together with glue between the layers. If I'd have had a set of the chisels I used, they wouldn't really be impractical to use - sharpness was good, and capable of more than most people actually achieve practically when they sharpen tools themselves.

Same one....

David Weaver

..the only practical way to grind them by hand is a medium crystolon in an oil bath. Diamonds row the steel some and I'm sure the mild steel backing will tear diamonds loose from a nickel plate over time.

If one was set up to sharpen them with the right setup, they really wouldn't be impractical at all - I just didn't have the urge to buy a set of them at $70-$80 each. The descriptions on buyee aren't usually accurate enough for me to risk sampling Iyoroi's version if I could find them.

high hardness makes things hard...

David Weaver

..to sharpen. If you tried to sharpen a 1095 blade right out of the quench of parks 50 (it must be 66 or 67 hardness), it is very difficult to sharpen. India stones don't take much of anything off of it and fresh sandpaper is slow.

I have an older high speed steel blade that was made in england and I thought it would be a barrel of fun to sharpen when I got it. Then at the same time that I bought the plane, I saw another listing with the same blade and it was used almost to the slot

I have no idea what type of HSS it is, but it wouldn't be hard to figure out if someone didn't already specify somewhere. The secret to it is that it's a touch on the soft side (not overly soft, but like the softer carbon steel irons that you find) and not bad to sharpen.

If those chinese irons were 60-61 hardness, I think they'd be fine to sharpen.

There's a point with aluminum oxide abrasives where things get just a little softer than a point and suddenly sharpening is very easily at the level that we do it (creating a burr and then refining). It's probably only a difference of 1 or 2 points.

I made an O1 and 1095 iron yesterday and quenched them both in parks 50 (which is a fast transition oil, so things end up a point or two harder than they would in soy oil or a slower quench oil) - after tempering at 400F, they're both still on the hard side and take twice as many strokes to sharpen as they would if they were a point or two softer (on india stones, or most anything that's not terribly slow).

So, kind of a two-fold thing - alloy and then hardness. High hardness and lots of vanadium is a real pain for anything other than diamonds or crystolon. I don't know that crystolon sharpens that stuff properly, but it seems to cut everything well. really high hardness does make it slower.

Re: Composition of YXR7

David Weaver

Thanks for the link, wiley. I should've been less lazy, as I've gone to Hitachi's site before for temper temperatures.

People need to be aware

Bill Tindall, E.Tn.

Crystolon is silicon carbide and not the more common aluminum oxide that woodworking stones are made from. Silicon carbide will sharpen carbide metal working bits, though now days diamond is used. So, of course, it will sharpen tool steels. However, in my limited experience no woodworker has one of these stones.

Re: People need to be aware

Warren in Lancaster, PA

Silicon carbide will sharpen carbide metal working bits, though now days diamond is used. So, of course, it will sharpen tool steels. However, in my limited experience no woodworker has one of these stones

Maybe not out in the boonies. Silicon carbide stones are very common, both oil stones and water stones. I have used them for 60 years.

no woodworker has which stones...

David Weaver

...crystolon?

They're standard stones in the norton oilbath trihones.

a carborundum style stone was popular in japan as a grinding stone or edge corrector.

The only stones I can recall being marketed at woodworkers and boutiquey folks are the sigma power II stones (sintered silicon carbide - and stu offered one as a waterstone) and CKTG and some guy named Ken Schwarz tried to market them under another brand for use with water.

The oilbath makes them work well - nothing else really does.

Forgot - the trihone was sold by lee richmond to woodworkers with a modified set of stones (common for chef supply is 2 crystolon stones and an india stone, but lee had them sold with medium crystolon, fine india and an oilstone of the buyers choice. The setup is superb for knives and superior to anything else for setting up japanese chisels for the first time because the bevel can be set flat quickly or even ground back by hand).

They're not marketed to woodworkers in general now (as in amateurs) as far as I know because they don't stay perfectly flat and you can't flatten them easily. For woodworking tools, though, they're miles better than diamond hones for bevel grinding when used in the oil bath, which solves the other issue with them - if used outside of an oilbath, they fracture and little bits of silicon carbide abrasive end up everywhere.

Carborundum corp made and sold gobs of them in the early/mid 1900s, but I'm going to guess by how little used most of them are when you find them, that craftsmen found the edge to be kind of brash and the huge amount of silicon carbide fractured bits that end up all over the tool and hands of the user is really offputting. They're extremely messy.

Not for your benefit, but for others reading, I would guess that it takes about a fifth of the time to set up a japanese chisel with a medium crystolon and india stone , and then some strong cutting natural oilstone vs. any waterstone rotation starting with a diamond hone. This may appeal to me since I buy, experiment with and resell so many tools. I don't care that the crystolon stones don't stay that flat because I don't use them to flatten the backs of tools (machine PSA aluminum oxide paper roll on a long run of glass is far better for that)

So, yes and no. Yes on the crystolon stones being marketed even in some cases directly to woodworkers, and no, they're not that common.

I forgot one other good example...

David Weaver

.the guy who got me into woodworking had a father in England who was a joiner by trade. He had really put some wear on the pair of metal planes that he had, as well as the two sharpening stones. He was old enough (probably would be about 100 now if he was still alive) to have done a lot with his tools.

The two sharpening stones were:

- a silicon carbide stone about like a medium crystolon (as old as it was, almost certainly carborundum corp)

- a washita

The friend and I (this is more than a decade ago now) looked through his stuff as it was brought here by the friend after he attended his dad's funeral. Both stones were dished in length (not width) and the carborundum stone severely. Being programmed modern paint by numbers sharpening systems, we were sure that this was an indication of the crude work being done by joiners.

I know better now. I could do quite well with that pair of stones if needed - one to set the bevel, one to hone the edge and then the far end of the stone where it rises above the dip can be used to remove the burr by running the flat side of the iron diagonally across it (This works pretty spectacularly, actually, if someone doesn't want to maintain flat stones in their length).

For anyone grinding an iron on site many times, a crystolon stone would've been a necessity.

For use in honing a knife, the medium crystolon is sublime. For all but the hardest of knives, it can reset a bevel with some pressure in about five swipes per side. The medium india (long stone, so long strokes on the stone) can refine that in about ten swipes, and the tip of the knife can be addressed with an arkansas stone or the whole bevel can be made to look nice for the prissy.

I'm sure...

David Weaver

..those stones were thrown away. My friend kept a stanley 4 from the kit, I have a record 5 1/2 from it that I have continuously tried to give back to him (I thought it a good idea to take it, recondition it and flatten it and give it back to him with new handles, etc - he refuses to take it).

I also have a slater bullnose. Had I not taken the record and the slater bullnose (which had no iron - first plane Iron I ever made, still works great), both would've been thrown in the trash.

Making a positive contribution

Bill Tindall, E.Tn.

I added to the knowledge at Woodcentral by pointing out that the stones David was using to cut these abrasive resistant tool steels is not made from the stuff most woodworking stones are made from. There could be the occasional boonie dweller that would not know this information and benefit from it. Can you point out a positive contribution your post made?

For the record, a boonie dweller 40 miles from where I live is a Society of American Period Furniture Makers Cartouche winner. Check out the desk in the Gallery made by Mayberry. He lives 15 miles distant. I could go on. For all our remoteness we turn out some fine woodworkers.

More likely in the boonies, too..

David Weaver

..the carborundum stones and norton types are likely to be found in any old boonies areas where there was a machine shop or carpenters.

It's actually a pretty good question as to whether any of the current "gurus" would teach use of a crystolon stone.

When I see the question come up about "what would be a good stone to use if I don't want to use a grinder", the answers are often everything but crystolon. And all of the everything but answers are poor answers. The stones need to be relatively new in my experience, though. I had a 12x2 or some weird size (not im-313 tri hone size) that was full thickness and very long combo medium india and crystolon coarse. it was bullet hard and did not release particles so it graded itself and clogged and seemed pointless to me. Similarly, the knife branded stones, "nubatama" or whatever went all the way down to about 36 grit silicon carbide to be used with water. I have no clue what good they would have been.