Shape of Tanto : Periodical Comparison
The Tanto(短刀) originated at some time from the end of the Heian to the early Kamakura period. Unlike the shape of Katana and Tachi, the shape of Tanto hadn’t changed dramatically because it was designed as a secondary weapon. But even the slight changes in the shape would give you an insight into the Tanto appraising.
The following breakdown shows the average cutting edge length and the size and the type of SORI(反り) for each period.
|Period||Cutting Edge||Sori Size
|1222-1289||21 – 26 cm||Very Shallow||Uchi|
|1290-1333||27 cm||None or Subtle|