Which metal uses pounds per square foot for gauging?

• A. Brass
• B. Lead
• C. Copper
• D. Aluminum

Answer: (B)

Lead is extremely dense, so expressing thickness by weight per area becomes the practical way to gauge it. In sheet metal practice, most metals are described by a thickness gauge, but lead is typically specified in pounds per square foot because a small change in thickness results in a large change in weight. For example, one inch of lead weighs about 59 lb per square foot, illustrating how weight per area directly reflects how much material is present. The other metals—brass, copper, and aluminum—are usually gauged by thickness with standard gauge or specific thickness measures, since their lower densities don’t necessitate using weight per area as the primary gauge. So the metal that uses pounds per square foot for gauging is lead.