M2 vs M42

[PJ Seiber]

I'm relatively new to this craft (2yr.). I'm wondering what your all's opinion is on the the best steel. Please chime in and let us all know what your opinion is. M2, M42. M42 with cobalt, cryogenic, Sheffield steel, and any other you can think of.

[Mel Fulks]

Real M-2 is good . There are ..or were , some supplier’s advertising that their steel was “ Same hardness as M-2” …..and it was , but it
did not leave a finish as good as real M-2 or T-1. Both are good , T1 will stay sharper longer than M-2. Cheap knives , even when
sharp ,often make for ‘tear -out’, as the steel is low. quality.

[Richard Coers]

Cheap knives , even when
sharp ,often make for ‘tear -out’, as the steel is low. quality.

Tear out is most often operator error in my opinion. Any kind of steel right off the grinder will cleanly cut wood. I mean the Egyptians turned wood after all and I assume they used some kind of hard copper alloy. I started turning with carbon steel, and once I learned to sharpen, even those worked quite well. Many will say you can even get carbon steel sharper. Carbon steel has worked for decades in a hand plane without tear out. Best steel? Of course each alloy can have benefits. It's like asking what the best car is.

[Neil Strong]

It depends...

Best steel in terms of edge durability?
Best steel in terms of edge fineness?
Best steel in terms of sharpenabilty?

On durability, you get different results with different cuts. I got the following results from my testing with heavy wing peeling cuts...

Heavy wing peeling cuts.png

With light finishing shear cuts you get a different result...

Light finishing shear cuts .png

With heavy push cuts in very hard woods I got a different result yet again...

Push cuts in hard redgum.png

The Tantung (Tt) performs better with the heavy push cuts but I found it didn't take and keep as fine an edge for the light finishing cuts in which M42 performed much better.

Fine grained Tungsten Carbide will cut for considerably longer yet again but it is much harder to sharpen.

[roger wiegand]

Neil, I'd be interested in your testing methodology-- is it published somewhere? You are seeing much larger differences than I might have expected based on my un-measured, anecdotal use of gouges made of different steels. My observations are completely without controls or experimental design, so real data are quite interesting.

[Mel Fulks]

I’ve tested steel machine knives by using them like “drawknives” . The real M2 and up will leave a shiny surface and cut without a lot
of force. In employments some shop owners who were using the steel that came with the machine were dealing with tear-out by
running everything through sanders . I proved that with good steel , that was not needed. But perhaps Robinson Crusoe got a
satisfactory shave with a shell honed on the best island rock.

[Reed Gray]

For 90% of my turning tools, I have either D Way M42, or Thompson V10. Simply, they cut longer without needing to be resharpened. I use the Big Ugly tool, a scraper for all of my heavy bowl roughing, I might sharpen it every 10 or so bowls, or at the half day point. Gouges for finish cuts, since they will cut more cleanly than scrapers, and clean up with a shear scrape. I can't tell any difference between the D Way and the Thompson tools for edge durability. I haven't done production work in maybe 10 years, and started using them maybe 15 years ago.

robo hippy

[Neil Strong]

Neil, I'd be interested in your testing methodology-- is it published somewhere? You are seeing much larger differences than I might have expected based on my un-measured, anecdotal use of gouges made of different steels. My observations are completely without controls or experimental design, so real data are quite interesting.

Roger

I've posted my testing protocol and results elsewhere. I can perhaps do the same here on this forum in a separate thread, but not immediately due to other commitments that I have at the moment.

My workshop experience is that I don't notice much difference between the different steels (with the exception of tungsten carbide). My workshop practice is to sharpen a batch of bowl gouges and go through them one after the other until they are all blunt then resharpen them together before starting to use them again. So, I get ample opportunity to observe how each performs one after the other. I have all of the steels that we use and and I still use all of them equally often.

Tool manufacturers will claim that their steel or heat treatment will outperform the tools from their competitors by factors of 'X', but I've never found those claims to hold up in practice.

Novice turners shouldn't get hung up on the steel in their first gouges, nor their heat treatments. They are better off buying additional gouges at less cost and experimenting with different flute profiles and grinds.

As a personal preference I like M42 for finishing cuts and V15 as a work horse steel, but find that flute profile and grind make a bigger difference than the steel, as does also the type of cut being used.

I'll leave you with one significant difference that I found in my testing and that was between Tungsten Carbide and the other two commonly used turning tool steels; V10 & M42, which performed about the same with this cut on very hard wood. I found that TC definitely outperforms the other commonly used gouge steels, but it is of course a useless bit of information until TC bowl gouge tips become more readily available to us...

Push cut test in hard wood.png

[John Kananis]

I'm curious if anyone knows where m4 (like the oneway mastercut gouges) fits into the mix.

[John Keeton]

I have D-Way tools (M42), Thompson (V10) and a few M2 only because the profiles of those tools are not available in higher grade steel. I turn a lot of hard maple and there is a great disparity in how long I can get clean cuts. I have to touch up the M2 tools after very few minutes, whereas the M42 and V10 retain a sharp edge for substantially longer. I haven’t done timed tests, but a guess would be a factor of 8:1. The M2 seem to take a nice edge. It just doesn’t last long. I understand that M4 is perhaps 2:1 on holding an edge over M2, but I don’t recall ever using it.

The cost factor of high quality tools is easily justifiable IMO. Except for some scrapers that don’t get a lot of use in my shop, I would never buy M2 tools if the profiles I like were available in CPM metal. I have asked Jimmy Allen of D-Way about making continental gouges, but he said they are just not economically feasible given the limited market.

[Brian Brown]

Yes, they are definitely selling stuff, but maybe this link would be helpful. I find their videos to be quite valuable.

https://www.youtube.com/watch?v=vcM6kStHhCw

[Neil Strong]

Yes, they are definitely selling stuff, but maybe this link would be helpful. I find their videos to be quite valuable.

https://www.youtube.com/watch?v=vcM6kStHhCw

Here is the chart from that video that Brian posted...

Some tool steel comparisons.jpg

It has M4 but not others like V10 that many of us use. Here is a chart that includes V10...

Tool Steel edge retention comparisons with M42.jpg
I've added where I think
M42 sits on that chart.

Edge retention or durability is what we woodturners mostly look for in a tool steel.

That chart is from the knife steel nerds and includes many steels that are not of interest to us woodturners, but here is the article it is taken from with more information on their steels than most of us woodturners will ever want to know!

https://knifesteelnerds.com/2021/10/...on-resistance/

PS You can see from that chart why I like V15...

.

[John Kananis]

What an amazing wealth of information you folks are. I've been eyeing up those d-way and Thompson tools, I'm going to add them 1 at a time as the need arises.

[Reed Gray]

I don't agree with his call on edge sharpness and the V10. The sharpening discussion comes up regularly, and the consensus seems to be that edge sharpness is pretty much the same for all metals that we use, but some are easier to get to that point than others. The tantung that I use on my Big Ugly tools is a coarse cast metal, but finer than the old carbide used on the older saw blades. I can hone it to an edge that will compare with any metal I have ever worked with. The CBN wheels have made a huge difference in sharpening. Sharpened on identical wheels, I can't tell any difference between V10 or M42.

I am not sure about the Oneway tools, though I do have one of their spindle detail gouges, and i tis one of the longer lasting edges. I had an old Packard gouge that was supposed to hold an edge '5 times longer' and didn't notice a lot of difference until I went back to an M2 gouge.

robo hippy

[John Kananis]

I found this and it seems (to me) the difference between m4 and m42 (from a metallurgical composition perspective only) is more molybdenum in m42 and more tungsten and vanadium in m4.

https://www.makeitfrom.com/compare/S...gh-Speed-Steel