O1 Tool steel

Re: Clarity about professional

ThomD


>I get Jim's point. It's the equivalent of saying small shops with handplanes can't deliver consistant results compared to big shops with planers. It ridiculous. How about the Japanese blacksmiths (or the ones at williamsburg, or any of hundreds of ABS members). You think they can't deliver consistant results?

Re: Clarity about professional

Teacher


>There's a difference between "CAN deliver" and "DO deliver." Do you really think the blacksmiths at Colonial Williamsburg consistently deliver blades that are exactly 1 3/4" with a precise 25 degree bevel and are hardened to RC 62? I don't either.

Re: Clarity about professional

Paul M. in San Diego


>Hi Thom,

I have seen multiple cases where Japanese blacksmiths produced inconsistent results. Some chisels arrive with very brittle edges and chip extremely easily. These go back to the source and are exchanged for equivalent chisels.

So in my opinion, there is quite a difference between mass produced and one-off when it comes to metalurgy. I still reach for my Japanese chisels first, as they are my favorites. When they are good, they're great. But some do arrive with poor metal quality.

Re:A-2 vs O-1 argument/discussion

George in Lowell, Mich.


>I can't hardly believe that I helped get this boulder rolling!!!!

"Don't use O-1, use A-2 it wears better."

My comment had to do with my using a scrub plane to flatten the top of my workbench. The top is red oak (30 years dry) and was put on the bench 5 years ago and used unflattened. I decided to plane it flat with the O-1 blade that I made and I was about 10% started and it was dull. I sharpened and did another 10%. I put in an A-2 (made by me)blade and finished the process without resharpening.

Admittedly no professional hardening and not a professional test.

I heated them both up to yellow hot (no magnet), and then plunged each into oil to quench. I know A-2 is air quench but the faster you cool, the smaller the carbide particles, is my logic. I do not temper which is another no no. I figure, why lower the hardness any. I have consistantly gotten no chipping and a hard edge. This process has been followed for about 20-30 blades of all sizes.

I again am not a professional heattreater but have been a machinist/toolmaker for about 30 years.

My comments came from my observations, and experience.

George in hot & humid Mich.

Re:A-2 vs O-1 argument/discussion *LINK*

Frank D. in Montreal


>Hi George,

A-2 vs. O-1 is one of those subjects that usually gets people going...

I don't doubt you got better results with A-2 but the suggested heat-treating process is quite complicated. It's also hard to judge the results of your comparison because there is no known reference point (you made the O-1 blade too). Anyway, I just wanted to stick in a link to Crucible Steel Co.'s recommendation for heat treating A-2. It's on the second page of the link; as you'll see it's probably out of reach to most people who don't have access to expensive ovens. Thanks for contributing to the discussion, it's always interesting to know what other people do.


A-2 data sheet

Re:A-2 vs O-1 argument/discussion

George in Lowell, Mich.


>Frank,

Thanks for the link. I especially liked the "tool steel comparagraph". It shows what I am refering to. We use alot of D2 to make the parts for our stamping dies that we use. Relative to steel types I have a piece of CPMM4 that I am making into a plane blade. I have a surface grinder at my disposal so sharpening is not an issue. I will have to get on the stick and get this machined and out to the heattreaters. I won't attempt to hand harden that steel. I will have to give a users report of this blade when I get it done.

George in now rainy Mich.

CPM M4

bill tindall


>Someone in our club is experimenting with this steel. So far it looks like it may be the ultimate for plane irons, but you will need diamond to sharpen it to its keenest possible edge. And you were wise to professionally heat treat it. The schedule is complex and required precise control to get best performance.