Founded in Milwaukee, Wisconsin, Master Lock revolutionized the security industry with its patent for the laminated steel padlock in 1924. Inspired by the construction of bank vault doors and battleships, Soref designed padlocks built from laminated layers of steel to replace the hollow-body padlocks of the era, which were easily shattered with a hammer.

Today, Master Lock operates as a subsidiary of Fortune Brands Innovations. Its reputation for durability was cemented by its legendary “Tough Under Fire” advertising campaign in 1974, which famously showed one of its padlocks remaining locked and functional even after being shot with a rifle bullet.

Master Lock’s product lineup includes:

• Traditional & Combination Padlocks: Used extensively for residential security, vehicle chains, and school or gym lockers.

• Industrial Safety (Lockout/Tagout): Specialized safety devices designed to disable power sources and secure industrial machinery during maintenance.

• Digital & Vault Security: Advanced offerings including Bluetooth-enabled smart padlocks, security safes (via the acquisition of SentrySafe), and key lockboxes.