Friden Model STW 10 Calculating Machine

This stepped drum full-keyboard electric non-printing calculating machine has a metal frame painted brownish gray (taupe) and ten columns of brown and gray plastic number keys, with a blank gray plastic zeroing key at the bottom of each column. Metal rods between columns of keys turn under the keyboard to indicate decimal places. A small brown and tan bar slides to the right to reset the decimal rods. The capabilities of the Friden STW-10 are quite similar to those of the earlier ST-10, although the exterior design and color are different. The model was introduced in 1949 and manufactured through 1966.
On the right are two columns of function bars. On the left is a ten-digit register that indicates numbers entered for multiplication. Below it is a block of nine white digit keys, with a 0 bar below. These are surrounded by three levers and four function keys.
Behind the number keys is a movable carriage with an 11-digit revolution register and a 20-digit result register. Taupe plastic buttons above the result register rotate to set up numbers. Ten numbered buttons under the revolution register are spaced between the digits. A zeroing knobs for the registers is on the top right of the carriage. All three registers have sliding decimal markers.
The machine has four hard rubber feet. There is a rubber cord and a tan plastic cover. A mark on the bottom of the machine reads: S82 (/) STW 10. The original serial number next to the model number has been effaced. Marks on the back and side read: FRIDEN. A mark on the cover reads: Friden (/) AUTOMATIC CALCULATOR. A mark on a sticker on the bottom of the machine reads: FRIDEN, INC. (/) SAN LEANDRO, CALIFORNIA, U.S.A. A mark on the cord reads: SINGER.
Compare MA*334379, MA*335419 and 1984.3079.04.
Carl Holm, “Milestones in the Development of Friden.”
Currently not on view
Object Name
calculating machine
date made
ca 1954
Friden, Inc.
Physical Description
metal (overall material)
rubber (overall material)
plastic (overall material)
overall: 21.7 cm x 46 cm x 36.8 cm; 8 17/32 in x 18 1/8 in x 14 1/2 in
place made
United States: California, San Leandro
ID Number
accession number
catalog number
maker number
Science & Mathematics
Calculating Machines
See more items in
Medicine and Science: Mathematics
Calculating Machines
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of The Singer Company, Friden Division
Additional Media

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