might be a silly question but.......

[loiner1965]

why are the different styles of hamon...grain....and tang shapes etc...is it just decoration or is they a purpose.

[paulb]

Steve,

not necessarily silly but a huge question. Hada is a result of the way different grades of iron/steel are stacked in a block, welded and folded. Different schools worked with different materials and assembled the blocks and worked the steel in different ways. Presumably this was because it added to the functionality and the aesthetic of the blade. Likewise hamon were develooped to improve the performance, durablitiy and beauty of a blade. Once again different schools developed their own unique style. Nakago shapes? I have no idea but probaby formed a non written signature identifying the work to a particular smith or school.

[John A Stuart]

Wow, no short answer really, except, it is like most things in art and manufacture. Things are tried that are innovative. If they work they are kept and sometimes improved upon. As defenses or style changes manufacture meets the challenge. Of course one tends to keep the techniques taught by the teacher as tried and true. Some innovation is purely artistic. John