friendly conversation on A2 and chipping

[Tom Vanzant]

George, interesting observation re: Chinese HSS. The subsea drilling industry uses 316L stainless steel in high pressure (5000psi) piping. My employer stopped using Chinese-manufactured components because they did not meet specifications, even though the parts were fully certified. Not only did the parts vary, but the certification was a complete sham.

[Lonnie Gallaher]

I did not comment, but my point was the properties sheet outlines a very controlled process for A2 steel. Not something for the hobbyist, unless you have the knowledge and back ground of some of the professionals here. Back in the early 1970's when I worked in a steel mill blacksmith shop we worked with simple tool steels. Our controls where by eye and experience and sometimes with a temp stick, using open atmosphere forges and furnaces. It worked for the time and the tools that we made. That environment would not work for the more modern tool steels.

[Tony Zaffuto]

As an aside to this steel discussion, if anyone here passes through PA on Interstate 80, my powder metal part manufacturing plant is at Exit 101 traveling to the West or Exit 97 traveling to the East. Consider this an open invitation for any to stop by.

[Pedro Reyes]

Pedro haha! I think we had the same thought at the same time...

Ha pretty sure you mean cake! then again the odds of two or more people thinking about cake in this forum at the same time are probably higher than we care to admit.

[george wilson]

Tom,certified by WHOM? By the Chinese? Forget it. Certified by suppliers with money to be made under the table?

[Matthew N. Masail]

Matthew: I asked WHICH woods are you planing. You answered end grain,which does not tell me which woods you are planing.

As mentioned,A2 should be made to uniform standards. The alloy recipe for different steels is a standard thing. That said,I have always found Chinese HSS milling cutters to be more brittle,and harder than USA ones. I do not know why that is. It could be that they ARE deviating from the standard recipes for HSS,or it could be that their heat treating practices are different from ours. I can't say. But,metals made in USA should be uniform.

Without being there and observing your sharpening angles and the quality of the edges you are making and how you use a bench grinder Matthew,and also your working practices,and what woods you are planing,it is impossible to diagnose why you are having problems. The only thing I can recommend from this distance,is for you to increase your sharpening angles.

Hi George, Your right. I answered "end grain" because I have used the plane on every wood under the sun (that I could get my hands on). pine, oak, beech, sapple, Ipe, blackwood and so forth...

My edges are very good I think, they cut everything very well, planes cut with little effort on pretty much all woods and end grain too. the bevel angles for planes are between 30-35, most closer to 30. I have checked and "know" the angle by feel on the stone.

the funny thing is that I have the Veritas low angle spokeshave with a A2 blade, it is honed at less than 25 and it holds up very very well with no chipping. I have only had 2 irons that chip badly all the time. the first was the A2 in my apron plane, the second an original Stanley blade in a no.4, it is such a lovely blade but will chip at anything less than 35, so it sits in a drawer at the moment. however I had an A2 iron in a woodriver no.4 that would micro chip like described in the video. it seems odd to me how some report great performance with a A2 iron honed at 25 in a plane, while others will say no less than 32. could it really such a variance in quality between 2 irons of the same make ? (like LV or LN)

[Tom Vanzant]

Certs from the Chinese suppliers, supposedly a pedigree paper trail from foundry melt through the final product, complete with lot-sample chemical and structural analyses. These Certs are part of the Data package that is supplied with all projects, providing traceability in the event of a failure in use. Our USA supplier ceased dealing in Chinese-manufactured parts when the fraudulent Certs were exposed. All affected parts were replaced, from A to Z, by our supplier.
We're off topic, so I'm done.

[Kent A Bathurst]

............and that depends upon standing on your left foot, with your right leg bent backwards at the knee, your tongue sticking out, with your head tilted exactly 17 degrees to the right, squinting cross-eyed and holding your breath-do that everytime and the results will be identical...........

It has been many posts since I had even the slightest bit of hope of following the technical details.

But this bit, Tony - I understand that completely.

Thanks

[george wilson]

I have never believed the certs on any chinese chuck,or whatever,that I have ever bought. I think they are all bogus. Remember the poison baby formula a while back?

[Peter Pedisich]

I have little knowledge of tool steels, but since I use primarily White Pine, my original Millers Falls and Craftsman irons hold up like the best Japanese hand forged steel!

[Tony Zaffuto]

I have never believed the certs on any chinese chuck,or whatever,that I have ever bought. I think they are all bogus. Remember the poison baby formula a while back?

Only as good as the American importer's on-site QC, and the integrity of the American company. Let's see.....baby formula, drywall. dog food and so forth.

[Stewie Simpson]

http://www.holteyplanes.com/tech_blades1.html

https://paulsellers.com/2014/04/edge...ith-a2-steels/

http://www.crucibleservice.com/esele...eralpart1.html

[Matt Mattingley]

There is a few things to consider. All Tool steels have a different application. A 2 when heat treated between 58 and 64 Rockwell then ground into a razor blade 25° or less the edge is nothing more than a bur. A very fragile bur. It will chip easy. 0-1 heat treating process is generally a little softer 56 through 58 Rockwell. 0-1 toolsteel instead of chipping tends to roll the edge. D2 and M2 will hold an edge better at the same Rockwell than A2 but with the sacrifice of even the steeper angle. Sometimes tempering, stabilizing, annealing, and the number of draws to toolsteel has a great effect in the performance. Most people these days don't want to pay for proper processing and alloying and the end consumer most of the time doesn't care where it comes from. Most offshore manufactures rapid bake and quench which leaves a hard candy coating in the 62-64 Rockwell which is way too hard but that's what you're left with which chips. A2 can be processed to 58-60 with a double draw and properly surface grinding away outside hard coating and would leave an absolute great attack angle at 30 to 32° with almost no chipping.

[Chuck Hart]

Where is Ron Hock when you need him. Anybody know him well enough to ask him about the A2 issue. I know he doesn't make his own steel but he buys it so he should know.

Chuck

[Chuck Hart]

I took this directly off Ron's web site:

AISI A2 differs from O1 with the addition of 5% chromium and 1.1% molybdenum, allowing it to quench in still air (“A” for Air.) While “stainless” amounts of chromium (12% or more) make tool steel “gummy” and hard to sharpen, the modest amount of chromium in A2 improves its toughness and abrasion resistance, but imparts only a slight measure of corrosion resistance (like high carbon steel, it will rust and appropriate preventative care must be taken.) But there is a trade off. During heat treatment the chromium addition combines with some of the carbon in the alloy to form chromium carbides – tough, hard particles dispersed through the steel. These carbides are the primary contributors to A2’s celebrated edge retention. However, during heat treatment, the chromium carbides can grow quite large – large enough to affect your ability to hone the edge as close to zero-radius as you may want. And these carbides are held in place with less strength than the rest of the steel matrix which can allow them to pop out under the stress of honing or cutting leaving a small gap in the edge. To strengthen the edge we recommend a larger bevel angle for A2 than we would use for O1. For a bench plane iron, try your A2 blade at about 30° or 33°. A chisel or block plane blade can be even steeper; try 35° or so and see if edge retention is improved.
A2 is one of the steels that respond well to cryogenic treatment. This extreme cold treatment (-320°F) essentially finishes the original quench, increasing the steel’s toughness without any decrease in hardness. You get increased wear resistance without any increase in brittleness so a cryogenically treated blade will hold its edge longer. You can keep working instead of sharpening. A2 is a great steel that offers a real improvement in edge retention. O1, on the other hand, is still preferred by many for its relative ease of sharpening and its ability to get sharper.

I hope this adds to the discussion