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.
Lafayette F-686.
Sans & Striefe Model 312.
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