The Builders Hardware Manufacturers Association (BHMA) has issued ANSI/BHMA A156.28-2007, American National Standard for Master Keying Systems. The publication updates the 2000 version of the standard and is available as a free download on the BHMA web site.
Master keying involves combining a group of locks or cylinders so each operates by its own change key, as well as by a master key for the entire group. ANSI/BHMA A156.28–2007 covers requirements for system design and design criteria to establish and maintain a secure keying system for building owners and managers.
Among the general updates to ANSI/BHMA A156.28:
• A number of definitions from ANSI/BHMA A156.30, Hi-Security Cylinders standard, and the American Locksmiths of America (ALOA) were added.
• The System Planning and Keying Conference sections were widely revised.
• The master keying schematics were improved.
