Begun, George M. “Making Your Own Punched Cards.” Journal of Chemical Education 32, no. 6 (June 1, 1955): 328. https://doi.org/10.1021/ed032p328.

George Begun used a template of "heavy galvanized iron" to drill holes into his 5 x 8" index cards to create his own edge-noted card system for use in his chemistry work. Rather than using commercially made sorting needles, he recommended the use of a ice pick with a dulled point "for safety".