Levi’s introduced the 501ZXX as a zipper-fly alternative to the button-fly 501 in 1954.
The classic 501 had long been associated with its button fly. Levi Strauss & Co. created the 501ZXX for customers who wanted the familiar fit and heavy denim associated with the 501 but preferred a zipper closure. The model is an important step in the company’s adaptation of its traditional workwear design to changing consumer expectations.
The “Z” in 501ZXX signals the zipper version. It should not be confused with Wrangler’s 13MWZ, where the letter appears in a different model-code structure. Later Levi’s models, including the 505, also became well known for zipper flies.
The 501ZXX belongs to the mid-century period when jeans were moving from specialized workwear into mainstream casual clothing and youth fashion.