Common Master Keying Book by The National Locksmith

This 184-page spiral-bound workbook teaches you to create master key systems from scratch. Instead of dense theory, you get practical worksheets, bitting charts you can photocopy, and real-world examples that show you exactly how commercial systems are built.

Work through exercises for 5, 6, and 7-pin cylinders. Learn to avoid the common mistakes that compromise security or create key conflicts. The "scan and print" section gives you blank forms for your own projects. Written by a locksmith with 40+ years of experience, not an academic.