Hand Tools

Photos for bill.. *PIC*

David Weaver
..I think sometimes bill doesn't believe anything I say. If I do manage to prove something, I think this changes my credibility next time zero!


Actually, I don't mind that - I don't think anyone should ever be let completely off the hook if they want to consider something proven or even very likely ((non?)professional courtesy leads to people taking liberties).

So, in discussing my 26c3 photo, the edge has little ridges in it. They're not an artifact of sharpening. I also saw a small increase size in snapped grain with 26c3 over O1. I found that kind of annoying, but because my process is good, I didn't jump to conclusions (just mental note to see if there's any micrographs later to show why I'm seeing that or if I have to consider expermenting forward).

Finding Larrin's micrographs showed that there are carbides in 26c3 large enough for me to see something like that occurring, but they're not too large.

I also have a cheap microscope ($425 shipped overnight from india - a spectacular deal). It's not believable to a lot of folks that it will take good pictures (it will, but what it lacks is the ability to take layers of pictures and tie them together to imitate a deep depth of field. At high magnification, the top of a very small scratched groove can be clear and the bottom blurry - it's that sensitive to depth).

Bill can let me know whether or not he believes that the carbides in some steels could be the cause of the damage (here are some in blue steel, which was regarded as ultra fine - I figured there was something wrong with the steel when I did the iron test because something is coming out of it and damaging the edge, and it's originating in the middle of the wear area sometimes. The fact that the cap was used probably exacerbates the effect in view because the shaving is holding whatever comes out against the iron.


I saw particles being released from other steels (including chinese HSS, and A2), but the effect on the surface was less.

Larrin saves the day again - by posting micrographs of carbides in blue and super blue steel - it is in fact the case that the tungsten carbides do not distribute neatly in little tiny carbides all over the place. What's the reason? I guess they form easily, and dissolve not so easily. I don't know. Larrin accepted the challenge to see if he could change process and get a better result (he could - what also seems to occur with poor dispersion is "carbide bands" that look like stellar belts. Not good). But, if Tsunesaburo does something with their more expensive tools to solve this, I don't know - I seriously doubt a $40 plane iron is getting more than punched out, hardened and tempered in a relatively quick process and ground on something that doesn't require much attention.

Larrin's micrographs show PM steel carbides nicely distributed, but some are larger than the particle size (this will happen when the steel is heated and it cools - at some point, they have to roll the steel, and then the processes used for the high alloy steels to normalize and soak and then austenize are at high temperatures - translation - I think the more PM steels are heated, the worse things will get. The fight then is between what it takes to get a strong structure vs. avoid carbide coarsening.

Bill mentioned 2 microns being about the limit that a researcher would see as a smudge, so I offered to retrieve 2.5 micron diamond grit if I could find it (this is from a lapidary supplier, so it's not junk - actually, you can see from the picture that it is really nicely done with very little in large individual particles that would scratch an edge - but we found the same with the suppliers 1 micron grit (which I have lost now) in that it made a scratch free (visible) surface on most of the iron backs.

So, here is a picture of 2.5 micron grit at 150x (the magnification that I always use).

And my microscope goes to a max of 600, so I took an additional photo of the diamonds at 600x)

© 1998 - 2017 by Ellis Walentine. All rights reserved.
No parts of this web site may be reproduced in any form or by
any means without the written permission of the publisher.