Padlocks come in various materials like steel, aluminum, and brass. They can be keyed differently, keyed alike, or master keyed. Keyed differently means each lock requires a unique key, while keyed alike means one key opens multiple locks. Master keyed locks allow a supervisor to open locks with a master key. OSHA requires lockout devices to be standardized, identify the lock user, and withstand force without a key. Brady padlocks meet these requirements and are available in security and corrosion resistant models.