Signature on Japanese blade. Opinion? Real?

[Sengoku]

Same as western sword makers cast billet of steel ground to shape on a machine
If you google wilkinson sword you can find photos of sword blades being ground to shape on large wheels

A cast and ground billet would shatter in use, one reason for the forging or rolling is to produce a more flexible steel blank. There are a lot of processes between cast iron and bar steel, most of them to reduce the carbon content to a usable level. The grinding is very late in the production line, more akin to polishing and sharpening than shaping. Hammering and rolling are faster, produce less waste and make for a stronger blade. I have had sword blanks from Wilkinson Sword, they are rolled/hammered to about 80% of final shape. See links below.

https://www.youtube.com/watch?v=XtpMAUf65UQ

https://www.youtube.com/watch?v=Wyk1NQZ9FqM

[nickn]

Actually the swords made by western makers like wilkinson or eickhorn are of a better quality then their Japanese counterparts which are crude in comparison

[nickn]

A cast and ground billet would shatter in use, one reason for the forging or rolling is to produce a more flexible steel blank. There are a lot of processes between cast iron and bar steel, most of them to reduce the carbon content to a usable level. The grinding is very late in the production line, more akin to polishing and sharpening than shaping. Hammering and rolling are faster, produce less waste and make for a stronger blade. I have had sword blanks from Wilkinson Sword, they are rolled/hammered to about 80% of final shape. See links below.

https://www.youtube.com/watch?v=XtpMAUf65UQ

https://www.youtube.com/watch?v=Wyk1NQZ9FqM

Good links
Non traditional Japanese swords would have been made in exactly the same way
There are photos on the net of lines of Japanese women doing the final polish on showato blades