Crown cork

A generic 21-tooth crown cork bottle cap.

The crown cork (also known as a crown seal, crown cap, metal bottle cap, or just cap) was the first commercially successful bottle cap design. It was invented by William Painter in 1892 in Baltimore. Painter had been working for years trying various bottle cap designs, with his company the Bottle Seal Company. After he patented the crown cork in 1892, which was an immediate success, he started a new company, Crown Cork & Seal Company (now Crown Holdings) which went on to become one of the largest manufacturing companies in the United States producing billions of caps annually.