Thread: Australian timbers and tool steels

On the Al content of River Redgum (well at least in the leaves, twigs and bark) see Table 3.4 in Chapter 3 of Eucalyptus camaldulensis (river red gum) biogeochemistry: an innovative tool for mineral exploration ....

Very little Al or Fe compared to other elements, and no Si.

Aluminium as an abrasive only gets traction when it combines with Oxygen to form Corundum, which requires quite high temperatures. it's a struggle to see how an Aluminium salt that might be drawn up by roots from the soil would convert into Corundum once in the tree. So, I'm rethinking what, if any, role Aluminium might play in the abrasiveness of woods.

Fe may be a better candidate in the form of Feric Oxide (such as Jewelers Red Rouge - FE2O3 - at 6 om Mohr scale).

And, of course, Silica if we can find any convincing evidence for its presence in tool blunting woods.

I'm also keeping in mind Kuffy's comment about the role of heat in blunting an edge.

Originally Posted by NeilS

I'm also keeping in mind Kuffy's comment about the role of heat in blunting an edge.

Neil and Kuffy

I can absolutely see why heat plays an important part in dulling edges of cutting tools with machines. For example the bandsaw on my timber mill has water streamed onto the blade to cool it otherwise it would heat to an unacceptable level, which is a quirk of horizontal bandsaws compared to vertical bandsaws.

I can see where metal on metal will generate heat such as filing a handsaw: Once striking a rhythm the repetition will generate heat.

However, can we generate sufficient heat and I stress the word "sufficient" with hand tools to worry the temper? We are not just talking uncomfortably warm to the touch at say 60C plus but a range between 175C (350F) to 205C (400F), which are the temperatures for tempering high carbon steel. HSS is in excess of this. In fact one of the advantages of such steel is that these temperatures don't worry it at all as anybody who has ground a cutting tool for a metal lathe will testify.

I am leaning more towards an abrasive and or chemical property within the timber resulting in premature wear or dulling. Howeve,r I have no idea what that may be other than wildly guessing.

Regards
Paul

Springback when hand planing causes decent friction and therefore heat right at the tiny micro thickness edge of the tool. It wouldnt take much to rub this super micro fine edge up to a heat level which was anything but ideal. And then it just melts away. This is wear, and it gets worse as things progress. I am not a supernerd, but it is my belief that toolsteel at 10C is more tougher than toolsteel at 100C. Harder timbers will springback harder onto the bevel right behind the edge making more heat than softer rubbish like pine.

Derek,

With regards to the silica content of Jarrah found in lateritic soils versus sandy soils, it might prove fruitful to simply look for glittery quartz like structures under the microscope of woods from two (or more preferably) different Jarrah trees. One grown in the State forest in the laterite clays and one from the sandy coastal plain. If you want some Jarrah from a known source, I have some from the State forest. A large old growth tree that was felled approx 10 years ago. Grew exclusively in clay. Shoudn't be too hard to source Jarrah from another known sandy source.

Regards,
Zac.

I couldn't positively identify the sparkles in cocobolo as silica, even under a microscope, because I have no clue how to prove that's what they are.

I think that's what they are, though. When you split a billet, you can pretty much tell how hard it will be on edges based on how sparkly it is. no sparkles, not as bad. Lots of sparkles, lots of little nicks in plane iron edges. Including high speed steel edges.

I'm also curious about what tints wood red in certain woods. like Jarrah (you could tell me an old wives tale about it being red due to iron oxide and I'd believe it) and some rosewoods.

Originally Posted by NeilS

And, of course, Silica if we can find any convincing evidence for its presence in tool blunting woods.

.

I know that plants such as wheat, rice and bamboo have very high silica content. Unfortunately we don't appear to have is readily available information on the silica content of our woods.

The following highly technical paper on the mechanisms by which silica is incorporated into plants also goes into the protective reasons why plants do this. The take-away message from that is that plants under attack and stress benefit from the protection effect of higher levels of silica.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2759229/

Our desert acacias, which are among our most tool demanding woods, do certainly experience the harshest of climatic conditions in which to survive.

Other threats, such as infestations, may account for higher silica content in some trees growing in more benign climates.

I'm swinging back to silica being the most likely culprit. As already pointed out, given its ubiquity, there will be enough of that in any soil type for uptake.

I'm increasingly doubtful that aluminium oxide (as Corundum) will be present, or be in sufficient quantities, to account for the abrasiveness of some woods, but I'm open to be convinced otherwise.

As for heat, I'll concede that hand pushed tools are unlikely to generate sufficient temperature at the micro edge to be destructive of itself. Perhaps, but unlikely, in the case of wood turning tools. But as Paul points out, HSS would require wood burning temperatures for that to happen. Mine get quite hot at times, but never enough for that.


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Originally Posted by NeilS

.......As for heat, I'll concede that hand pushed tools are unlikely to generate sufficient temperature at the micro edge to be destructive of itself. Perhaps, but unlikely, in the case of wood turning tools. But as Paul points out, HSS would require wood burning temperatures for that to happen. Mine get quite hot at times, but never enough for that.....

Neil, somewhere, a long time ago, I read that edges can experience sufficient local heating to encourage deformation in the tool steels commonly used in hand-tools. Can't remember where I read that, nor how reliable it might be. It's certainly true of cutting edges in powered tools, of course. One of the reasons Carbide cuts better than tool steel, despite not taking as 'keen' an edge is that it doesn't deform at the temperatures generated at router-bit or TCT saw blade edges.

I'm not sure I'm ready to lay all the blame for edge-destruction at the feet of silica; I'm prepared to accept it's a major player, but clearly there are other factors at play. What we need is a good scholarly article written in language we can understand, that sets out all of the components that contribute to 'hardness' in wood. If such a thing exists.....

Cheers,

Originally Posted by IanW

Neil, somewhere, a long time ago, I read that edges can experience sufficient local heating to encourage deformation in the tool steels commonly used in hand-tools. Can't remember where I read that, nor how reliable it might be.

now that is an interesting qualification.

as far as I know, the use of high speed steels in hand tools dates back to the mid to late 1990s.
I don't think the use of HSS would be classed as "common" even today. HSS being the alloys used by Veritas and Lie Nielsen.
I suspect that some large percentage of the world wide market for hand tools is still based around "normal" low carbon steel, but I have no data to quantify this other than the observation that the big box retailers don't stock hand tools from the premium makers.

so it's quite possible that what you remember reading is correct.

I just want to clarify something...

I don't know many different steels, and practically zero outside of woodworking, so can I sidetrack here and just get someone to either verify or correct my understandings about steel types...

O1 and L6: high carbon tool steels
A2: tool steel which has been hardened following a cryogenic treatment process
M2 and D2: High Speed Steels
PM-V11: league of its own, powdered steel. Neither HSS nor TS
Tungsten Carbide: Not steel at all due to lack of iron

Anyone?

Originally Posted by Luke Maddux

I just want to clarify something...

I don't know many different steels, and practically zero outside of woodworking, so can I sidetrack here and just get someone to either verify or correct my understandings about steel types...

O1 and L6: high carbon tool steels
A2: tool steel which has been hardened following a cryogenic treatment process
M2 and D2: High Speed Steels
PM-V11: league of its own, powdered steel. Neither HSS nor TS
Tungsten Carbide: Not steel at all due to lack of iron

Anyone?

My understanding of L6 is that it's a lower carbon high toughness steel that's often used in bandsaw bands and saw blades (I didn't check that, could have it mixed up with something else). I haven't seen it used in good woodworking edge tools, but it would make a decent abuse-intended knife. W1 and O1 are considered high carbon tool steels. W1 is more like old cast steel, probably - average of 1% carbon (old cast steel would've been graded and separated for use with the highest quality stuff going for razors, then files, and down from there, etc.). O1 is more modern and more stable but with more alloying in it.

A2 is an air hardening tool steel that my understanding was developed for diemaking or something of the sort. Very stable hardening - low warpage (thus toolmakers favor it). Cryogenic treatment can be done to anything, and isn't done to all A2 (as in there is no special link to Cryogenic treatment and A2, except that a lot of A2 is cryogenically treated). The earliest I've seen of it (cryogenic treatment) is henckels friodur razors - I believe they are 440C. It causes the non iron-carbides to disperse more evenly within the steel resulting in an ability for the steel to take a reasonable edge and not fail with chips and nicks as much (i.e., it makes the steel a little bit more uniform). I have seen someone doing the same to O1 recently, can't remember who. It was popular in friodur razors because rust is a problem for poorly looked-after straight razors, and 440C is very rust resistant. It also had a terrible reputation for sharpness, but the cryogenic treatment along with apparently making it a couple of points softer than carbon steel razors made for a rust resistant razor that could be sharpened on natural stones (natural stones dominate razor finishing and have until recently when amateurs have taken over - synthetics are easier to use when you're starting off and you need paint by number to use and buy).

D2 isn't a high speed steel, but another diemaking steel. More chromium than A2 and higher carbon and more wear resistant. It was developed as a low cost high speed steel, but didn't work out due to inability to maintain hardness and toughness at working temperatures. Still a diemaking steel. Has a reputation for losing its initial edge (because it fails in bigger particles than good A2 and especially than the high carbon steels) and the maintaining that half dull edge for a long time due to wear resistance. M2 is a molybdenum high speed steel - someone can correct me if I'm wrong, but it probably replaced the original tungsten series steels because they were expensive to produce - they are (steels like T1) a much better blade steel than M2, though - finer grained. No clue if anyone is making anything from something like T1 steel. High tungsten steels were tried early-mid century on razors, but never caught on because they really don't have anything to offer a shaver above and beyond carbon steels and they are harder to sharpen and maintain and less receptive to a strop.

I don't know the exact composition of PM V11, but it's probably similar to 440C. Someone on another forum had it tested. It's a more wear resistant version of A2 without chippy/chunky behavior because of how it's made. It is a good blade steel. Mine does not rust - I remember the composition discussion being centered around it being high chromium, and it does feel like it is when it's on a stone (A2 sharpens more easily on natural stones and feels closer to carbon steel...and it is closer to carbon steel).

No thoughts on the tungsten carbide other than how nice it works in power tools and metal cutters as long as the cuts aren't interrupted. It is a bit brittle, but definitely hard and long wearing.

Originally Posted by Luke Maddux

Anyone?

O1 and L6 are oil-hardening steels.
A2, D2 and less frequently L6 are air hardening steels. A2 and D2 are typically quenched in still air, L6 can be quenched in forced air.
M2 and other M series steels are referred to as high-speed steels. M42 for instance is used to make metal cutting bandsaw blades. I have some Lenox blades that are made of M42. Their Rockwell C hardness is around 30 but they cut tough materials like 304 stainless and 4140 (used for axles, gun barrels and my saw-smithing hammers) with ease.

None of the alloys you mention are plain carbon steels. The 10XX steels are plain carbon steels where XX is the approximate carbon content. 1095 for saw blades and many smiths use 1045 for hammer heads. 1018 steel is 'mild steel'. Quench in water for small parts and oil for thicker sections.

Here are the alloy compositions.

Steel compositions 062717a.jpg

Originally Posted by Luke Maddux

PM-V11: league of its own, powdered steel. Neither HSS nor TS

Anyone?

Luke, PM is a metal forming process with particular benefits for the resulting steel. TS is produced with a PM method, as are many different compositions of HSS.

https://en.m.wikipedia.org/wiki/Powder_metallurgy

Apologies in advance for a very small digression. I have a report on the potential for milling desert species of timber from Western Queensland. It identified these species as having limited potential: Limited in the sense it might suit down trodden farmers in desperate times. These were the species:

Milling desert species.png

Some properties were identified, but alas nothing to do with why they may blunt tools:

milling desert species properties.png

and lastly a few pictures 'cos we all love pix.

desert species.jpg

I can see you will need to click and enlarge them.

The report in fact concentrated on Gidgee and Mulga.It used to be available on the net, which is where I found it and downloaded it some while ago, but the link seems to have disappeared. It was entitled "Utilisation of Western Queensland Hardwoods as specialty timbers" by Venn, McGavin and Leggate. It is extensive and goes into the viability of milling (primarily with a portable sawmill), seasoning and potential markets.

I think you may find the hardness figures interesting in the second chart.

Regards
Paul

Hi IanW - am having trouble following some of the instructions on this site - however, I hope this reply works.
If you wish to work old dried A. rhodoxylon, try soaking it in water for 24 hours or so. I found, many years ago, that cutting 30+ years old posts with a chainsaw had the effect of removing all the teeth from the chain (plus lotsa sparks) - then one day I needed to again cut an old Rosewood post and found that the saw acted as though the post was green. An irrigation sprinkler had been running for 24 hours nearby and the spray had fully covered the pile of posts.
I also have an old hand saw that cuts through dry 20 years old local Rosewood better than a chainsaw.
Discussion up thread refers to different growing areas and how the timbers react. I think my observations may show that to be true, as the firstmentioned 30+ years old posts were from a more coastal area.
I have a nice whip handle I turned, back in the late 60s - shame I had to use it on a bull that thought I would make a great fence accessory - the split was glued with ordinary old Aquadhere and has stood the test of time (but no more use as a donger of bulls).
Cheers.