Underwood Sundstrand Adding Machine Value Guide

The Underwood Sundstrand Adding Machine is a landmark of office engineering, featuring the revolutionary 10-key layout designed by Oscar Sundstrand in 1914. This specific model, produced between 1930 and 1945, represents the era when Underwood dominated the market after acquiring the design to replace cumbersome full-keyboard machines.

What affects the value of Underwood Sundstrand Adding Machine?

• Mechanical functionality, specifically the smooth operation of the printing mechanism and crank handle.
• Cosmetic condition of the black enamel finish and the clarity of the numeric key legends.
• Presence of original components such as the paper roll holder and internal ribbon spools.
• Market demand for early 20th-century American office technology, currently valued between $75 and $82.

How to Identify Underwood Sundstrand Adding Machine?

• Look for the distinct black metal chassis with a side-mounted manual crank handle.
• Verify the 10-key numeric layout, which was the first of its kind to replace multi-row decimal keyboards.
• Check for the Underwood Sundstrand branding typically located on the front or rear of the steel and cast iron frame.
• Identify authentic Bakelite keys and rubber feet consistent with mid-century manufacturing materials.

History of Underwood Sundstrand Adding Machine

Designed by Oscar Sundstrand in 1914, this machine revolutionized the industry by introducing the 10-key layout that remains the standard for numeric keypads today. Previously, adding machines utilized full keyboards with rows for each decimal place. The Sundstrand design was so successful it was acquired by the Underwood Typewriter Company in 1927, which dominated the office equipment market for decades.