There is a slightly other interpretation of the 3rd and 4th kanji
mentioned in "Sakutô no dentô-gihô" (作刀ã®ä¼çµ±æŠ€æ³•, page 3-34):
å®ç²Ÿ
Which read as "Shiso". A brief translation of the text (it refers to a
ken by Ômi no Kami Hisamichi) reads:
"He made swords just by the use of high-quality steel which
came from Shiso district of Harima province. For tantô, ken, or yari,
inserting a shingane is not absolutely necessary. This ken was made
from so-called ´Shiso-gane´, which is steel of the supremest quality
and which he proudly states via the signature."