HSS vs KYRO vs PM........

[odie]

Aside from a few older carbon steel tools, all my lathe tools to date are HSS (high speed steel).

I'm considering getting a bowl gouge in KRYO, which involves super cold temperature treatment, or PM powder metallurgy. (I'm assuming PM, is the same thing as MIM, or metal injection molding.....right?)

Now, I'm sure most of us have heard the claims about edge holding ability for KRYO and PM, but other than that, I'm unaware of any real testing of how well these edges will hold up under wood lathe use. Anyone know of any independent testing that wouldn't be influenced by a biased need for a particular outcome.....?

Then, there's the ol' HHS......and, to tell you the truth, when compared to HSS, I would be very critical of the KRYO, or PM advantages......unless there is REAL and USEFUL edge holding ability. Claims that these technologies hold edges 2-3 times longer than HSS is pretty meaningless, once wood fibers begin to tear. As far as I'm concerned, sharp is sharp.......and anything less than that is.....well.....not sharp!

HSS has always been a very useful lathe tool steel for me......easy to sharpen....holds the edge well. I usually sharpen bowl gouges the first time it's used on any particular bowl......and during the course of bringing that bowl to finish, I re-hone several times, but not re-grind. With scrapers, I regrind up to about a half dozen times for one bowl. This is only a minor inconvenience, because I've got my "system" down to a science......it's very very fast. I'd say traditional grind gouges are back on the lathe in less than a minute. Ellsworth grind gouges (or those ground in that manner) are back into play in less than 2min......and scrapers are back in use in less than 15 seconds!

With the speed in which I can get a dull tool back into play, the only real reason to think about some other steel, is to eliminate the inconvience of stopping to resharpen......it won't mean a darn thing in the overall time I spend completing a bowl.

I suppose I'm asking for opinions on these tool steels, but I'd sure like to see where someone has systematically made a useful analysis......

opinions, and/or otherwise ?

otis of cologne

 

[Steve Worcester]

Kryo with a "K" is a manufacturer who uses cryogenic tempering, and PM is powdered metal as you state but comes in varying degrees of metal combinations. I use almost exclusively PM tools and many that are cryogenically treated.

In PM, M4 ,xV are the most popular. With the "x" in xV, the higher the number the greater the vanadium content. This allows the tool to hold an edge longer before needing to be resharpened.

I have a Kryo gouge, several Oneway Master cuts (M4) a few Glasers of different metals and lastly, the Thompson gouges. As the others wear out (a long time with the amount of gouges I have) I will replace them with Thompsons. Personally, I like the flute design better, it is cleaner, is a 10V steel and is about the best I have used.

You may want to check his FAQs
http://www.thompsonlathetools.com/faq.asp

 

[LHauch]

Okay, so I'm a tool junkie, with a good paying job to feed my habit.
I have an assortment of Crown-ProPMs, Hamlet ASP2030, and Henry Taylor Kryo bowl and spindle gouges to go along with some Sorby (and from my beginning days, Benjamin's Best) HSS tools.

There is no apparent difference between the more expensive tools - there is a big difference between them and the HSS tools. I've had some really nasty wood that took the edge off in about 90 seconds using the HSS tools, while I was able to get a full 5 minutes with the more expensive tools on the same piece.

That said, on normal wood that doesn't dull the tools, I can do a full rough cut on a large bowl (12" dia.) or vase (10" - 12" tall), before hitting the grinder before the final cut, while I have to sharpen the HSS tools at least one extra time.

I've never hand any problems using my 1750rpm 60 & 100 grit AO wheels for sharpening. (Some folks say you have to use a slow speed grinder, but I have not had any problems.) While it takes less than 2 minutes to put a fresh edge on the tools, it does interrupt my work rhythm.

If you have more time than money, then HSS is probably a better way to go, if your time is more precious than the extra cost, then PM, ASP, or KYRO are a better choice.

 

[odie]

That said, on normal wood that doesn't dull the tools, I can do a full rough cut on a large bowl (12" dia.) or vase (10" - 12" tall), before hitting the grinder before the final cut, while I have to sharpen the HSS tools at least one extra time.

If you have more time than money, then HSS is probably a better way to go, if your time is more precious than the extra cost, then PM, ASP, or KYRO are a better choice.

Hi Larry......

This is one aspect of personal observation I was attempting to find with my original post.

If you have to do one extra sharpening during the process of making one bowl, is it really worth it to have the more expensive tool? Now, I certainly could see the argument for spending the extra money in order to sharpen less....but, if the act of sharpening tools is to the point where it's automatic, precise, and fast......well, I'm wondering if there is any benefit that isn't just limited to a couple of minutes of your time per bowl......?

There is one other thing........I acknowledge that there are times when you just hate to break concentration, stop the lathe, and resharpen. That thought deserves to be considered in this thread, too.

I've never hand any problems using my 1750rpm 60 & 100 grit AO wheels for sharpening. (Some folks say you have to use a slow speed grinder, but I have not had any problems.) While it takes less than 2 minutes to put a fresh edge on the tools, it does interrupt my work rhythm.

Larry, I don't know what diameter wheels you're using, but I sharpened on a 3350rpm 6" grinder for many years before I switched over to the 8" slow speed 1725rpm Delta. I've found that the higher speed, but smaller diameter wheels are perfectly suitable for sharpening lathe tools......with one caveat: You learn to do a smooth grind at a faster swing of the tool......can't dawdle! I think I would hate to have a 3350rpm 8" grinder for this purpose......but, I've never tried it!

It's possible I've misinterpreted what you said, and you do have a 1750rpm grinder.......in that case, it's considered to be a "slow speed" grinder, even though there are other grinders that are slower yet.

otis of cologne

 

[waltben]

There have been a couple of lab type tests of several (but not all) different kinds of hardened tools, including one where they cut sections of tools to analyze them. All I know is from my own empirical experience, and I really don't like stopping to sharpen a tool when I'm working on a piece, unless it's really huge.

I've several M2 tools, including my SRGs, but gave away my M2 bowl ones. I've tried M4 but found the two 1/2 inch ones I tried to be only marginally harder than M2 in spite of the advertising claims. 2030 and Crown's powdered tools are very close to the same hardness and the ones I like most. Thompson, 2060 and the harder Glasser tools are quite similar, but too hard for me to hone after grinding or to resharpen in a reasonable amount of time (use Tripoli and diamond rouge on cloth buffing wheels). I've settled on a pair of 1/2 inch Hamlet 2030s for my Stubby and a pair of Crowns for my mini/midi work place. I can turn almost anything without having to stop and sharpen with them and if I have to switch to the second gouge, it'll feel and act the same as the first. (I've also got a 5/8" 2030 and a 3/4" Thompson for the Stubby.) I use smaller bowl gouges occasionally, but no where near as much as the 1/2 and 5/8 size. That's where I want to keep sharpening time down.

 

[robo hippy]

I wore one Ellsworth gouge down to a triangle tool, and a second one is close. I have one of the Packard and one of the Oneway 'lasts 5 times longer' gouges. I also have 4 of the Thompson, and 2 Glaser. I like the profiles on the Thompson better, and they and the Glaser hold an edge much better than any of the others. The HSS may take a bit finer edge, but wearability isn't even close. If I ever need any more gouges, they will be Thompson. Even in the most abrasive woods, they last.
robo hippy

 

[Barry Elder]

Odie, do you really think professional lab test results have any real meaning in the wide world of woodturning? IMHO, lab tests can tell you about the characteristics of the metal itself, but absolutely nothing about the abilities of the woodturner to use any particular tool, and nothing about the piece of wood being cut.

I bought a set of 2030 steel tools from Packard a few years ago, just for the heck of it I bought a gouge from a guy in the Pac NW whose name I cannot find, and have bought several tools from Thompson Lathe Tools. All of these tools have been highly satisfactory. For the best $ value, tools produced by independents like Doug Thompson are better than paying investor dividends and golden parachutes that we have all been paying the last 12 years or so.

FYI, I use 1/2 and 5/8 gouges for roughing and experimenting and don't sharpen very often, sometimes only once every two or three days. For finish cuts I use 3/8 gouges and sharpen as necessary for the finish I need.

This information is from my personal experience and I have no financial interest in any of these companies, and it is free and therefore you are hereby permitted to extract any value you are able to!

 

[Bill Blasic]

When it comes to turning tools and various steels I am hardly an authority, but I do know that the moment that I started using a Thompson tool it changed the whole turning outlook. There is absolutely no doubt in my mind that a Thompson tool stays sharper longer than any other that I tried. Doug Thompson is in a couple of the same clubs as myself and at one of them he passed out tools to try, I missed that meeting. The next meeting I didn't ask to try but bought one or two based on two things - the price and Doug's conviction to bringing a quality tool at a reasonable price to the everyday turner. I have not looked back since, most of those pre Thompson tools have been donated to the raffle table or given to new turners in the club to get started with. My latest turning philosphy is that one cannot have too many Thompson tools. My next Thompson purchase is a 1/2 skew that I will pick up at the next meeting.

 

[Gordon Seto]

Cryogenic treatment of materials is a process that uses cryogenic temperatures to modify materials to enhance their performance. Materials commonly treated are all metals such as aluminum, steel, stainless steel, copper, titanium, brass, tin, etc., some plastics, carbide, and others.

I think "Kryo" has become the catch phase for advertising turning tools. Some you have to dig deep to find out what steel their Kryo line was made out of. A lower quality steel with enhancement is not the same as high quality steel with the same enhancement. I doubt cryogenic plastic or aluminum turning tool would have the same wear resistance as those made out of 10% vanadium steel.

 

[Doug Thompson]

Now, I'm sure most of us have heard the claims about edge holding ability for KRYO and PM, but other than that, I'm unaware of any real testing of how well these edges will hold up under wood lathe use. Anyone know of any independent testing that wouldn't be influenced by a biased need for a particular outcome.....?

Then, there's the ol' HHS......and, to tell you the truth, when compared to HSS, I would be very critical of the KRYO, or PM advantages......unless there is REAL and USEFUL edge holding ability. Claims that these technologies hold edges 2-3 times longer than HSS is pretty meaningless, once wood fibers begin to tear. As far as I'm concerned, sharp is sharp.......and anything less than that is.....well.....not sharp!

Powder metal is a great idea that allows higher percentages of alloys in a steel that can't be done with standard methods. All the elements are formed into a fine powder then mixed and placed into a form under pressure/heat until the elements bond to each other. The quality of steel is much higher but is expensive to do.

Cryogenics is advertised as a process to create a super steel from common steel, if a steel really lasts 2 -3 times longer just because of a cryogenic treatment why spend the extra money to buy better steel. Cryogenics will improve the characteristics of a steel, it's noticeable cutting wood but you need the carbide forming elements in the steel before it can work. Cryogenics won't make a super steel it just makes the steel better.

Testing like Alan Laser's article last year is good so we can see what elements are in the steel that we buy but the real test is how well steel holds up to wood. I though I would have a test ready this summer but it will have to wait until more cash is available, this can done at the AAW offices with the local club running the test.

Grinding wheels and grinders are up to the individual, basically it's what you learn to use. Six or eight inch wheels, high or low speeds will work fine but a 8 inch slow speed grinder is the best to learn on.

A sharp tool is needed for a finish cut to reduce sanding, professionals sharpen before a finish cut and some keep one tool set aside just for the finish cut... it doesn't matter how it's done as long as the tool is sharp.

We talk about different steels all the time but the bottom line is the higher quality steels hold that really sharp edge longer.

 

[Howard Beaver]

Reading this thread makes me wonder if I'm sharpening enough!. I started with a cheap set of HSS, my wife gave them as a present a year before I had a lathe! I graduated to Sorby HSS tools and thought that was a fantastic improvement. Last summer I got a couple of Thompson gouges, and realized what I have been missing. My vote (with limited experience acknowledged) is with the Thompson tools.

Howard

 

[odie]

Powder metal is a great idea that allows higher percentages of alloys in a steel that can't be done with standard methods. All the elements are formed into a fine powder then mixed and placed into a form under pressure/heat until the elements bond to each other. The quality of steel is much higher but is expensive to do.

Cryogenics is advertised as a process to create a super steel from common steel, if a steel really lasts 2 -3 times longer just because of a cryogenic treatment why spend the extra money to buy better steel. Cryogenics will improve the characteristics of a steel, it's noticeable cutting wood but you need the carbide forming elements in the steel before it can work. Cryogenics won't make a super steel it just makes the steel better.

Testing like Alan Laser's article last year is good so we can see what elements are in the steel that we buy but the real test is how well steel holds up to wood. I though I would have a test ready this summer but it will have to wait until more cash is available, this can done at the AAW offices with the local club running the test.

Grinding wheels and grinders are up to the individual, basically it's what you learn to use. Six or eight inch wheels, high or low speeds will work fine but a 8 inch slow speed grinder is the best to learn on.

A sharp tool is needed for a finish cut to reduce sanding, professionals sharpen before a finish cut and some keep one tool set aside just for the finish cut... it doesn't matter how it's done as long as the tool is sharp.

We talk about different steels all the time but the bottom line is the higher quality steels hold that really sharp edge longer.

Thanks for your input here, Doug......

If you've been following along, you'll know that, to date, all my tools are HSS, with the exception of a few older ones that are carbon steel. Many of the tools I have now were purchased in the 1980's and 1990's......so, this may serve to help explain why it's taken me so long to consider the newer tool steels, and methods of processing them......I've probably got 50 lathe tools of various configurations on hand, and if it weren't for a desire to experiment with a few new grind shapes, and to leave my existing bowl gouges with the current grind intact, I could go for quite some time before I really NEEDED to purchase any more lathe tools.

Your whole post is geared to explain why KRYO and PM tend to give quality tool steel an edge that lasts longer. I've heard enough comments from others, that I believe it's true.......no disagreement there.

I probably will purchase one or two new bowl gouges in the near future, and they will likely be PM/KRYO.....but my concern has been, do I really need KRYO/PM? The newer KRYO/PM tools will not be sharper than HSS, but the sharp edge will last longer......but how much longer, and to what degree does this equate to be useful???? If we are talking an average of one extra full sharpening during the course of making one bowl, and that sharpening costs you on average of about two minutes, or less.......well, you can see where my reasoning has taken me.

Now, for a new, or fairly new turner who is still struggling with their sharpening techniques, I can see how anything that will keep them on the lathe and off the grinder, will be of great significance to them.

I'm not attempting to trivialize the importance of the newer tool steels and the technical advances in their processing.........what I'm wondering is, for someone who can sharpen quickly, efficiently, and precisely.......are they as significant of advances to the seasoned turner as they likely are to the novice?

otis of cologne

 

[Doug Thompson]

Just a fast reply, break time from milling tools (for Jimmy Clewes) Who would ever have thought...

Most professionals only use a couple tools all the time and I'll be the first one to say don't buy a lot of tools. One bowl gouge is enough to turn a bowl...

Yes, Cryogenics and PM are the best qualities for turning tools, how much longer will the sharp edge last over HSS is unknown except A-11 will last longer than anything on the market today, 15V was the leader but it's not on the market now. The test I want to do will give us a better idea how they compare to each other. Sharpening is not a race, speed comes with experience and practice, the longer you turn the easier it is to get the grind needed. BTW - no one turns or grinds the same way, you learn to use the grind you create.

I started to turn using Craftsman tools then went to Henry Taylor's, the jump to Glaser tools was huge and I never looked back. Matter of fact I own 11 old Glasers and 4 are still in the original package (that's a sign of a tool hoard)

 

[john lucas]

I've read all the metalurgy concerning the new tools. I was not convinced from all the posts because there seemed to be a lot of bragging, more like I now have this new tool from state of the art metal so it must be better. I resisted for quite a while.
All I can say is the more I use my Thompson tools the more I like them. I was turning a lamp tonight out of old balusters. They are covered with paint and have been on the buildings for 40 years. They eat up the edge of a tool. I was switching back and forth between my thompson tool and another brand HSS tool. I would get one partial cut with the HSS tool before it litterally would not cut anymore. I mean the gouge would not cut more than about 3" and would not remove all the paint before it simply would not cut. With the Thompson gouge I would get at least 3 and sometimes more. This stuff is brutal on the edge until you get past all the paint and first 1/16" of the wood. I switched back and forth between the 2 tools and the Thompson outlasted the other one every single time.
I also have less problems with the Thompson gouge clogging. I'm not sure whether it's the shape of the flute (I have the V) or the black coating but it does work. I have 5 different bowl gouges the other 4 simply don't stand up to to the Thompson tools.

 

[steelguy]

HSS vs KRYO vs PM ......

I am a five decade, passionate woodturner as well as a steelmaker and am responsible for technology functions at Crucible – the U.S. manufacturer of CPM M4, 10V, 15V. We also make high carbon tool steels, and highspeeed steels such as M2. I am a strong believer in the right materials for the right application and realize that our ciustomers must receive value for their $. Our 137 year history is based on matching material needs with real application performance.

Relative to performance of advanced materials: There is a 30+ year history involving the use of PM tool steels in all manner of tooling applications, including wood processing. Jerry Glaser was the first to apply CPM 10V (generic version – A11) to turning tools. It is a very highly alloyed steel with a high percentage of wear resistant vanadium carbides. It will run the pants off of M2 tooling - so will many other high performance grades such as ASP 2030, 2060, and CPM M4 – if wear is the controlling mechanism.

As to cryogenic treatment of tools, there are metallurgically sound reasons to use cryogenic treatments during the heat treating process. Many PM materials have been cryogenically treated for years as part of good basic heat-treating. All Glaser tools have been cryogenically treated for 20+ years. The “as advertised†grades used in many cryogenic treated tool brands seem to be A2 and M2 – pretty traditional materials. There is much debate as to the metallurgical relevance of cryogenic treatment of tools as a post heat treatment process. In some limited cases it can improve the hardness of materials at the risk of chipping - if the original heat treatment has resulted in significant quantities of retained austenite (a steel phase which forms hard, but brittle martensite upon rapid cooling.)

My own personal goal is to sharpen less and turn more. I do not enjoy multiple grindings because it takes time, and radically shortens the useful life of a tool. Many custom gouges have wonderful starting “signatureâ€profiles that are difficult to maintain, unless you have expert sharpening skills. Again my personal goal is to seldom touch the grinder with my tools and keep them tuned up by honing (diamond slip stone). “Hone-a-lot, grind-a-little†should be every turner’s motto.

As to recommendations on tooling materials: 1) never buy a tool unless the manufacturer tells you its actual alloy designation; 2) always buy at least M2 tools, and preferably the highest alloy material you can afford; 3)save your dollars on elegant handle systems by making your own; 4)eventually purchase at least one weighted handle tool to see if you really like it – they have an amazing feel.

It is great to see so many discussing materials!

Jerry Wright

 

[MichaelMouse]

Jerry Glaser was the first to apply CPM 10V (generic version – A11) to turning tools. It is a very highly alloyed steel with a high percentage of wear resistant vanadium carbides. It will run the pants off of M2 tooling - so will many other high performance grades such as ASP 2030, 2060, and CPM M4 – if wear is the controlling mechanism.

Yep, there's the key. Any alloy you buy will dull on dirt.

I think its a tempest in a teapot. I am still using tools that came with my first lathe. Carbon steel, easily freshened with a cone and stone, never subjected to jigging, jiggling and grinding, merely passed over the wheel once or twice and back to work. My big M2 rougher eats a lot of dirt, and has been sharpened down an inch in the last fifteen or so years. Has at least the same left. Of course I'm a couple hundred pieces a year, not a month, but I also cut my firewood, which isn't as clean as something you buy at Woodcraft.

 

[john lucas]

The best thing I ever did for my turning was to look at tools as consumables. Yes you are going to use them up. It let me sharpen more frequently instead of worrying about using up my tools. What this did was remarkable. First, I was always using a very sharp tool. This makes turning so much more relaxing. You aren't as tired at the end of the day and your cuts are much more accurate with less tearout.
Second. I learned how to sharpen. By sharpening so frequently I quickly learned how to get a keen edge while removing the least amount of steel. I'm always amazed how long a tools lasts. I turn a lot, and still my bowl gouges last for many years. I'm not sure how long but in 15 years of very active turning I've only used up 3 bowl gouges. These were not high quality gouges so they needed sharpening more often.
I do use jigs now because they are very fast and remove almost no steel if done with a touch. Sharpening frequently in the beginning taught me to sharpen free hand which I value and still use on certain tools.
I turn a lot of brass, aluminum and other nasty materials as far as edge holding is concerned. I had one Kryo tool and gave it away. I couldn't see that it had any real advantages to my other tools. The PM Kryo tools on the other hand are remarkable. I don't notice a huge difference when turning regular woods, simply because I sharpen so much. When turning these nasty materials or abrasive woods I notice a large difference.

 

[Donna Banfield]

That's interesting, John. Someone told me the same thing a while back, an individual whose opinion I highly respected, and from whom I learned a great deal about woodturning. Turning tools are a consumable, just like sandpaper, but you won't go through the tools as quickly as your sandpaper.

And you're absolutely right! Once you stop worrying about using a tool up, you tend to relax a little more. Your cuts are better and sharper because you sharpen more often. You also tend to spend less time sanding because your cuts are much better -- you're really cutting the wood, and not scraping or tearing at it because your tool is dull. Forcing a dull tool into wood comes with a whole lot of consequences.

If you want to 'save' a tool, don't use it. Otherwise, why did you buy it?

 

[Malcolm Smith]

Seems pretty well covered though a couple of considerations might have bearing. There is a considerable price difference between the fanciest and the bargain tools sitting at the dealers but if one sharpens a lot less often, the fancy tools last so much longer that one hasn't realy saved money by buying the bargain tools. How much steel one wastes in the sharpening would have some bearing on this.

Nearly all the tools I use are Glaser and since I sharpen with a Tormek system there is little or no waste in the removal of steel. Even with the very highest skill, sharpening at a high speed grinder, some steel is wasted.

The other factor that comes to mind is the mention of regular steel tools. We all used them years ago and I hear the argument that they take a better edge. Even if this is true, and one can question it, that edge difference would dissappear almost immediately. The other problem is that sharpened on a high speed grinder, the temper of regular steel is quickly lost. Even the exotic steels should be treated very carefully at a high speed grinder and should not be dipped to cool them which can cause minute cracks. Though I have a couple of high speed grinders, I only use them if a lot of steel has to be removed from a tool when it is first bought.

The Oneway system that balances the wheels makes a considerable difference.

Malcolm Smith.

 

[odie]

Great comments everyone........

I was beginning to think I was missing out by not having any tools that were any more technologically advanced than HSS.......but, the comments I'm hearing today tend to vindicate me (I think! )....perhaps I'm a little outdated....but still, my sharp HSS will provide results equal to whatever the more advanced steels are capable of.

Sharp is sharp......just sharpen more often and you don't give up a thing!

I believe I'll eventually venture a PM/KRYO purchase, but I really don't think I'm missing out on anything......other than convenience.

Enjoying this thread. Looking forward to more comments.......

otis of cologne

 

[robo hippy]

As a production turner, I would rather sharpen less.
robo hippy

 

[Alex Ku]

I wish all tool manufacturers indicate where they buy steel. You can buy M2 steel made by a Chinese manufacturer or by Crucible Company here in US.
Guess which steel will be better.
Another important thing is heat treating. No matter how good is your steel is bad heat treatment will kill it.

BTW Recent test on knife forum showed that classic D2 steel with good HT outperformed CPM(3V if I am not mistaken) steel. I guess CPM steel was not treated properly.

In other words: buy your tool from someone you trust. Who does not make a secret where he gets his steel and how heat treatment is done.

 

[Doug Thompson]

I wish all tool manufacturers indicate where they buy steel. You can buy M2 steel made by a Chinese manufacturer or by Crucible Company here in US.
Guess which steel will be better.
Another important thing is heat treating. No matter how good is your steel is bad heat treatment will kill it.

BTW Recent test on knife forum showed that classic D2 steel with good HT outperformed CPM(3V if I am not mistaken) steel. I guess CPM steel was not treated properly.

In other words: buy your tool from someone you trust. Who does not make a secret where he gets his steel and how heat treatment is done.

Alex, I'm glad you brought this up, steel is just the starting point the heat treatment either makes or breaks the steel... I could only imagine the heat treatment on some of the tools we buy. Which brings up another point, I found out years ago a Glaser tool cut wood like butter and walked away from the lathe that day with one thought... that was to easy. There's a reason some tools cut better than others and it has to do with the steel they are made from. I don't say this because I sell tools, (if you don't know me I give my profits away and raise a lot of money with these tools) but why waste time on cheap steel. We spend thousands on a lathe, chucks and all the other stuff yet go to Harbor Freight for tools and wonder why we have trouble cutting wood...

 

[john lucas]

I don't think you can compare a knife to a turning tool for edge holding. The cutting angles and cutting speed is totally different. I do think there are some correlations between the two but I don't think you can lay down a hard fast rule. I have some high carbon steel tools and they do cut cleaner when freshly sharpened but only for a very short time.
I tried to find out why they seem to feel sharper and went to all of our various labs that have microscopes. I could not find one that would give me the magnification that I needed without destroying the tool or modifying the microscope (which they wouldn't let me do) so I still haven't been able to look at the grinds under high magnification.

 

[Bill Blasic]

For anyone sitting on the fence about buying a Thompson tool go to this link, this should sum up Doug's convictions on his tools.
http://www.thompsonlathetools.com/guarantee.asp

 

[John Nicholas]

Longer Time at the Lathe

I probably will purchase one or two new bowl gouges in the near future, and they will likely be PM/KRYO.....but my concern has been, do I really need KRYO/PM? The newer KRYO/PM tools will not be sharper than HSS, but the sharp edge will last longer......but how much longer, and to what degree does this equate to be useful???? If we are talking an average of one extra full sharpening during the course of making one bowl, and that sharpening costs you on average of about two minutes, or less.......well, you can see where my reasoning has taken me.

Now, for a new, or fairly new turner who is still struggling with their sharpening techniques, I can see how anything that will keep them on the lathe and off the grinder, will be of great significance to them.

I'm not attempting to trivialize the importance of the newer tool steels and the technical advances in their processing.........what I'm wondering is, for someone who can sharpen quickly, efficiently, and precisely.......are they as significant of advances to the seasoned turner as they likely are to the novice?

Otis turn your argument around. If a tool will keep a novice turner at the lathe longer, then it should also work for an experienced turner.

John

 

[odie]

Otis turn your argument around. If a tool will keep a novice turner at the lathe longer, then it should also work for an experienced turner.

John

Hello John.......

In this case, it doesn't work that way. Please read my post on how long it takes me to resharpen a tool. This is very unlike what someone who is new to sharpening experiences.......and since I re-hone bowl gouges at least a couple of times between sharpenings, I'm getting a long service life out of a single sharpening.

otis of cologne


By the way......I just placed an order for a Hamlet 2060 3/8" PM bowl gouge. I plan on doing some testing of my own soon. If I'm wrong about what I've been expressing on this thread, I'm not one who would be unwilling to acknowledge it......and you all must be realizing by now that I'm just not the type who will "go along to get along"!.....but, I'm fair and analytical.

OOC

 

[Doug Thompson]

This is good now you can compare 2 different HSS's, The M2 has about 2% vanadium and the 2060 has about 7% so there will be a difference. Let us know your test results.

 

[odie]

This is good now you can compare 2 different HSS's, The M2 has about 2% vanadium and the 2060 has about 7% so there will be a difference. Let us know your test results.

According to the information I have on the Hamlet, it's also powdered metal technology (PM)......which means it will be much more than simply comparing HSS to HSS.

otis of cologne

 

[MichaelMouse]

I don't think you can compare a knife to a turning tool for edge holding. The cutting angles and cutting speed is totally different. I do think there are some correlations between the two but I don't think you can lay down a hard fast rule. I have some high carbon steel tools and they do cut cleaner when freshly sharpened but only for a very short time.

My theory, and it would have some logical, if not physical evidence to support it, is that carbon steel, with its lower wear resistance, wears faster against the stone, giving a sharp edge sooner. Of course it also wears faster against the wood, a disadvantage.

Bit of a primer on some of the qualities of steels here. http://www.crucibleservice.com/eselector/general/generalpart1.html

Though they're steel sellers, the argument for PM steels equally alloyed being superior in wear resistance due simply to better carbide distribution is logical. By the same logic, the average carbon steel edge will be more irregular, and give your thumbnail a bit more bite. After all, it's the finest stropped edge that cuts you without your even feeling it.

 

[n7bsn]

I wish all tool manufacturers indicate where they buy steel. You can buy M2 steel made by a Chinese manufacturer or by Crucible Company here in US.
Guess which steel will be better.
....

In other words: buy your tool from someone you trust. Who does not make a secret where he gets his steel and how heat treatment is done.

I left the last to point something out.

Everyone appears to accept that you can get some really poor quality product from China, what many fail to realize this that they can also get product that is truly astounding.

Consider this; you own a Chinese steel plant, producing a run of steel for the Chinese military. Are you going to cut corners on that, when the government has a tendency to execute the owners of firms that sell the government products that fail to meet specs’?

China (un-officially) couldn’t give a #($%& if you sell a sub-standard product outside of China. But inside, especially for Government use, is a different story

 

[Doug Thompson]

According to the information I have on the Hamlet, it's also powdered metal technology (PM)......which means it will be much more than simply comparing HSS to HSS.

otis of cologne

I shouldn't have confused the matter with that statement, Jim Staley took the time to classify all the steels we use at the symposium last year, they are HSS and I don't have time to look for it.

The general term we use for HSS and then specify M2, M4, 2030, 2060, A11 etc is the way woodturners break down the different steels. The added vanadium in the 2060 will be the difference you will see and the edge will last longer.

Hopefully STEELGUY could add to this or correct how the different steels are classified.

 

[Steve Worcester]

According to the information I have on the Hamlet, it's also powdered metal technology (PM)......which means it will be much more than simply comparing HSS to HSS.

otis of cologne

They are all high speed steels as it is a classification of metal content.

 

[odie]

They are all high speed steels as it is a classification of metal content.

Very true, Steve......with the distinction that the Hamlet 2060 is also PM, or Powdered Metal technology. In that sense, it doesn't share the same properties as any of the other HSS steels I've been using in the past......it will be interesting for me to try this tool out, so that I can have some "stick time", rather than theory.

otis of cologne

 

[John Nicholas]

Hello John.......

In this case, it doesn't work that way. Please read my post on how long it takes me to resharpen a tool. This is very unlike what someone who is new to sharpening experiences.......and since I re-hone bowl gouges at least a couple of times between sharpenings, I'm getting a long service life out of a single sharpening.

Ok! Put some numbers with it. A novice that starting turning in the last year spends 10 minutes per hour sharpening. I've been turning for 4 years so, I sharpen about 5 minutes per hour. And you have it down pat, so you spend 1 minute per hour.

If any of the 3 above buy a tool that requires less sharpening, then that person spends more time at the lathe and less at the grinder. The logic applies to me reducing my 1/12 of the time spent sharpening, as it does to someone spending 1/6 of their time sharpening.

The issue is how much weight one chooses to allow to the time reduction.

John

 

[Doug Thompson]

They are all high speed steels as it is a classification of metal content.

I looked and couldn't find Jim's chart online but M2 through 2060 are HSS, now 10V (A11), 15V are classified as tool steel.

 

[john lucas]

It's actually more about turning than sharpening. Well OK they both relate but what I meant was when your are turning your sort of in a groove with the tool, your body and the shape of the piece all coming together. When you stop to sharpen you sort of interrupt that process and have to get back in the right frame of mind. So the longer you can go without sharpening the smoother the flow of lines seem to be.
Of course sometimes you do need to back off and relax. This is where I will take a couple of tools over and sharpen. I purposely put my grinder several feet from the lathe to allow me to relax on the walk over.

 

[steelguy]

Hss Vs Kryo Vs Pm

HSS or high speed steel refers to a class of tool steels which have high hardnesses at red temperatures and hence can be used to cut othe metals. They also have high carbide contents for wear resistance. HSS can be made conventionally via ingot metallurgy or as PM where liquid metal is gas atomized into spherical particles which are canned, heated and hot isostatically pressed (HIP). The PM materials are much tougher than equivalent compositions made conventionally. Compositions are as follows:

Alloy C Cr W Mo V Co HRC
TOOL STEELS
O1 0.9 0.5 0.5 - - - 56-58
A2 1.0 5.25 --- 1 0.3 - 58-60
D2 1.5 11.5 --- 1 1 - 58-60
CONVENTIONAL HIGH SPEEDS
M1 .83 3.75 1.70 8.50 1.15 - 62-66
M2 .85 4 6 5 2 - 62-66
PM HIGH SPEEDS
M4 1.4 4.0 5.5 5.25 4.0 - 62-66
Rex 45 OR
ASP 30 1.3 4.0 6.3 5.0 3.1 8 67
Rex 76 1.5 3.8 9.8 5.3 3.1 8.5 68
ASP 60 2.3 4 6.5 7 6.5 10.5 68
PM HIGHLY WEAR RESISTANT TOOL STEELS
10V 2.45 5.25 --- 1.3 9.75 - 60-62
15V 3.45 5.25 --- 1.3 14.5 - 60-62

* typical application hardness

Jerry Wright

 

[odie]

HSS or high speed steel refers to a class of tool steels which have high hardnesses at red temperatures and hence can be used to cut othe metals. They also have high carbide contents for wear resistance. HSS can be made conventionally via ingot metallurgy or as PM where liquid metal is gas atomized into spherical particles which are canned, heated and hot isostatically pressed (HIP). The PM materials are much tougher than equivalent compositions made conventionally. Compositions are as follows:

Alloy C Cr W Mo V Co HRC
TOOL STEELS
O1 0.9 0.5 0.5 - - - 56-58
A2 1.0 5.25 --- 1 0.3 - 58-60
D2 1.5 11.5 --- 1 1 - 58-60
CONVENTIONAL HIGH SPEEDS
M1 .83 3.75 1.70 8.50 1.15 - 62-66
M2 .85 4 6 5 2 - 62-66
PM HIGH SPEEDS
M4 1.4 4.0 5.5 5.25 4.0 - 62-66
Rex 45 OR
ASP 30 1.3 4.0 6.3 5.0 3.1 8 67
Rex 76 1.5 3.8 9.8 5.3 3.1 8.5 68
ASP 60 2.3 4 6.5 7 6.5 10.5 68
PM HIGHLY WEAR RESISTANT TOOL STEELS
10V 2.45 5.25 --- 1.3 9.75 - 60-62
15V 3.45 5.25 --- 1.3 14.5 - 60-62

* typical application hardness

Jerry Wright

Thanks for giving us that chart, Jerry.......

I'm assuming the HRC references hardness by Rockwell scale.....is that correct?

If so, then I'm also assuming the Hamlet ASP 2060 steel is the same as the ASP 60 on the chart.....? Looks like it's Rockwell 68, and the hardest steel on the chart.....ought to withstand wear pretty well. I also think it may (or may not) be a slow steel to sharpen well.......? (Anyone know about that?)

I also understand that PM has, to some degree, been plagued with chipping. I'm not really sure how that happens. Is the chipping generally caused by sharpening, usage while cutting wood on the lathe.....or careless handling?

I'm far from being knowledgeable in the various steels available to turners.....and I use, or will be using a very old fashioned way to make judgements about them.......I'll use them and see if I like them! If it passes MY testing, I might buy some more!

An explanation of all the abbreviations at the column top would be useful. (thanx)

For me, this is becoming a very interesting thread......

otis of cologne

 

[john lucas]

Has anyone heard of chipping of the pm steels. I haven't. I've been using them for a while now and pretty much abused them by turning solid aluminum, brass and some extremely abrasive woods.