Quote Originally Posted by JDM61 View Post
i cannot remember the correct Japanese name, but i have read that the little "fingers" of clay that reach down toward the edge of a Japanese sword from the thicker application of clay up on the shinogi are done specifically for that purpose. If you get a crack on the edge, it will not propagate because that little "cell" created by the slightly softer area. Thats is just what I read somewhere. Not sure if it is accurate as really top drawer nihonto rely as much if not more on the fact that they are made out of at least two or sometimes three different types of steel each having a different carbon content.
Close, but no cigar. Not even close actually.

1) The thing you mentioned are called ashi, and indeed they are little thin lines that are less hard , and they serve the purpose of stopping chips on the edge side. They have nothing to do with the sword itself breaking or not, at all. If a sword is going to break, the ashi will not stop that in any way.
2) ashi are needed on both high end nihonto and low end.
3) all nihonto have the 2 types of steel design.
4) the ashi are unrelated to the fact that there is a different type of steel at the core.
5) nihonto are not inherently superior to modenr monosteel katana. The 2 different types of steel are used because that was the best way of doing things at the time, with the primitive materials and understanding they had. Today, things are still being done that way because that is the only way a licensed smith is allowed to make a sword in Japan, by law. Any non traditional sword is not a cultural artefact but an illegla weapon.
6) A modern mono steel katana will outperform the best nihonto

Look I don't mind discussing things, that's what we are here for, but you really seem to have a tendency to talk about things you heard of but don't understand, and then make conclusions that don't make sense at all. Please, you mentioned wanting to learn to make razors, then stick to actually making razors and learning things, instead of only talking about things without learning anything.

The only things we care about here is what people do, learn, and see themselves.
So I suggest you start doing things and stop the trivia time because it is serving no purpose.

Make something and tell us how it went and why it worked or not. THAT is useful discussion.