Meaning of base box

base' box"

Pronunciation: [key]
  1. a unit used in the sale of tin plate, equal to the total area of 112 sheets each measuring 14 by 20 in. (35 by 50 cm), or 31,360 sq. in. (196,000 sq. cm).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.