IBM adopts an 80-column punched card that only its machines can read
Inventor Clair D. Lake’s narrow rectangular holes won a contest inside the company because they could go into production quickly, and the cards became a large business for IBM in their own right
- Patent: US 1,772,492, “Record sheet for tabulating machines”
- Filed 20 July 1928, granted 12 August 1930
- Rows: 10 for coding numbers in 1928, 12 in the modified card of 1930
- Mid-1950s: card sales made up roughly 20% of IBM’s revenue and 30% of its profit
Choosing Lake’s design tied customers’ records to IBM’s own equipment. A business whose files sat on IBM cards could process them only on IBM machines, and every new record meant buying more cards, so revenue continued after each installation. A rival tabulator maker could not read those existing files, which raised the cost of switching supplier.
“a greater quantity of perforated data upon a record card of a given size without sacrificing card strength or durability”Clair D. Lake, IBM inventor, in his patent application filed 20 July 1928
IBM put a new punched card into use in 1928 with 80 columns of narrow rectangular holes. The card it replaced carried 45 columns of round holes, and IBM says the change doubled the data each card could hold.
Clair D. Lake’s patent application describes why the round holes could not simply be made smaller. Packed closer together, a row of small circles tore like a perforated stub, and cards punched that way were not satisfactory in the machines. His answer was a slot stretched in the direction the card traveled through the tabulator.
A contest inside IBM
Lake’s slot was one of two proposals. According to IBM’s history of the card, Thomas J. Watson Sr, then head of the company, set Lake and a second inventor, J. Royden Pierce, to work separately, with only one design to go forward. Pierce kept the round holes and let each stand for more than one character. Lake’s route meant building new punches and readers, yet James W. Bryce, the inventor Watson asked to decide, backed it as the faster one to bring to customers.
The winning card worked only on machines IBM made. For almost half a century, the company says, its cards held most of the world’s stored data, until tape took over.
Sources
- IBM, “The punched card”, IBM Heritage, accessed 22 October 2026. https://www.ibm.com/history/punched-card
- Clair D. Lake, “Record sheet for tabulating machines”, US patent 1,772,492, filed 20 July 1928, granted 12 August 1930. https://patents.google.com/patent/US1772492A/en
