『NIIGATA CHISEL MARKS』

1: 富石 (TOMIISHI). One of my favorite chisel blacksmiths in Niigata. The full name of Ishida blacksmith is 石田富吉(Ishida Tomiyoshi). He makes chisels that rival Tokyo chisels. Learned the blacksmith’s full name from Mr. Tamon Taniguchi’s comment.  Thanks to Mr. Tamon Taniguchi for the sharing.

2: 日本号 (NIHONGO). This chisel is also made by the blacksmith 石田富吉(Ishida Tomiyoshi) . Marks 1 and 2 are his most common marks.

5: 國慶 (KUNIKEI). Common mark in KUNIKEI chisel. This one made by the third generation KUNIKEI. KUNIKEI chisels are also comparable to Tokyo chisels.

7: 清久 (Kiyohisa). Common mark in KIYOHISA tools. The blacksmith's name is 渡辺清栄(WATANABE KIYOE). 

9: 元寿舟弘 (GENJU FUNAHIRO). Common mark in FUNAHIRO tools. The blacksmith's name is 船津祐司(FUNATSU YUJI). According to Ishikoso-san's research, the steel used for the chisel of this mark is white No. 1(C 1.38% vacuum arc redissolved). If the Chinese character on the mark is just 舟弘 (FUNAHIRO), the steel used is common white No. 1(C 1.32%). Link for the research: https://www.jstage.jst.go.jp/article/dougukan/25/0/25_2501/_article/-char/ja

11:海弘 (UMI HIRO). The Umihiro brand chisels from the Sanjo area in Niigata Prefecture have a long history. Its origins can be traced back to the 10th year of the Taisho era (1921), when it was founded by Yamada Chojiro“山田長二郎” (who passed away in the 16th year of the Showa era, 1941).
The second-generation Umihiro was Yamada Chojiro's eldest son, Yamada Yuichi“山田勇一”, who was born in the 38th year of the Meiji era (1905). Yamada Yuichi's younger brother, Yamada Tsunegoro “山田常五郎” , went on to found the Tsunehiro“常弘” brand of chisels. In May of the 48th year of the Showa era (1973), the second-generation Umihiro, Yamada Yuichi, had to stop working due to a sudden cerebral hemorrhage.
His son, Yamada Kenichi “山田賢一”(born in the 9th year of the Showa era, 1934), continued the craft as the third-generation Umihiro. In some contexts, you might find Yamada Kenichi referred to as the fourth-generation Umihiro; this is likely because Yamada Chojiro's father, Yamada Tsunekichi“山田常吉”, is sometimes counted as the first generation. Yamada Tsunekichi was also a blacksmith; he studied the making of traditional Japanese locks (Wajo) and traditional cold weapons before eventually shifting to making chisels.
Unfortunately, there is currently no additional information available to help determine exactly which generation of blacksmith made a specific piece based solely on the Umihiro maker's mark.

12: 常弘 (TSUNE HIRO). The blacksmith's name is Yamada Tsunegoro “山田常五郎”. His father was Yamada Chojiro, the founder of the Umihiro brand. In terms of price, Tsunehiro chisels are currently arguably among the most expensive in the Sanjo region. This is not only due to their exceptional quality—his chisels are said to possess outstanding edge retention, much like the renowned Kiyotada chisels (though I have not verified this personally)—but also because his working career was relatively short, resulting in a very limited production volume.