Ryoba Noko Japanese Both Sided Hand Saw Hand Saw By Yamakuchi Sukezaemon - 210mm

Smith name: Yamakuchi Sukezaemon (山口介左衛門, 1911~1975)

Steel: Carbon Steel

Cutting edge length: 210mm

Total length: 453mm 

Blade thickness: about 0.45mm

Blade width: 73~90mm

Weight: 90g

Blade sharpening and adjusting: Yamakuchi Sukezaemon

Manufacture Era: Before 1970s

Accessories：-

Additional Information: Unused and in good condition, though it shows some minor surface rust. It was sourced from the same professional tool shop in the Kanto region as the Yamaguchi Sukezaemon Douzuki I previously listed. I acquired this recently, and it is the last saw by Yamaguchi Sukezaemon that the shop had in stock.

This saw has been well-preserved. Crucially, it has never undergone Metate (sharpening/tuning) by any other craftsman. It perfectly retains the original edge and finish directly from Blacksmith Yamaguchi.

I consulted Mr. Tsuchida regarding this saw, and he shared some key insights that are not mentioned in any publicly available online records. I would like to share those exclusive details with you here.

1. Technical Lineage
   Yamaguchi's technique was most heavily influenced by Oba Shoichiro  I (First Generation), despite the fact that Oba never officially accepted him as an apprentice.

2. Steel

   Unlike other blacksmiths who strictly adhere to specific grades like White Paper (Shirogami) No. 1 or No. 2, Yamaguchi did not limit himself to a fixed steel type. Instead, he would visit material suppliers regularly to personally select and test the steel before purchasing.

   While the specific batches varied, it is certain that he exclusively used carbon steel, never alloy steels like Blue steel (Aogami).

   According to Mr. Tsuchida, the master hammer smith Kozaburo often encountered Yamaguchi at steel shops in Sanjo, testifying to his rigorous selection process.

    

3. The Secret of "Nagagire" (Edge Retention)

   According to Mr. Tsuchida, Yamaguchi aimed for a higher degree of hardness during the heat treatment process. 

   Naturally, despite this extreme hardness, the steel retains excellent toughness (tenacity) to prevent the blade from snapping—a balance similar to that of Kiyotada chisels, which are also renowned for their exceptional edge retention.

   However, this hardness made the manual scraping process using the "Sen" tool incredibly labor-intensive. The hard steel created significant cutting resistance and caused the tool to slip easily, requiring immense skill and time to finish.

   Furthermore, the tooth profile is designed to be more robust than the overly slender teeth commonly found on the market. This specific cross-cut tooth geometry was also favored and recommended by the master smith Miyano Tetsunosuke.