5.17 Relay-Ricoh, Japan

Following World War II, Nippon Slide Rule Company (1948 to 1950), later San-Ai Kekki Ltd. (1950 to 1958), produced Relay slide rules which were exported to the USA as Relay Industries. In 1958 the company became San-Ai Measuring Instruments. In 1963 the San-Ai Group joined Riken Optical Co., which eventually became a part of Ricoh Ltd. Ricoh supplied slide rules to many companies in the USA and Europe, such as Compass, Lafayette, Lutz, Sans & Streiffe, Staedtler Mars, and others.

Lafayette F-686.

Sans & Striefe Model 312.

Total number of Relay/Ricoh slide rules in the collection: 4. \(~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\)

Model		Year	Serial	Typ	Mat	L0	Case	Note
F-686		1961	J.S-3	L	bb	10	yes	Lafayette F-686, Vector Log rule; nice condition
99-7030		1965		L	bb	5	yes	Lafayette 99-7030; table of gauge settings, equations on back; Unitrode advertising on case; owner Richard T. Schroeder
150		1972	US-6L	L	bb	10	yes	Sans & Streiffe model 311; very nice condition
151		1974		L	bb	10	yes	Sans & Streife model 312; no date code

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