Locksmith & Physical Security Technician Guide: How to Start in Locks and Door Hardware is a practical introduction to the skills, knowledge, and mindset needed to begin a career in locksmithing and physical security. The book explains how locks work, how door hardware systems function, and how technicians diagnose, repair, install, and maintain security components in residential and commercial environments. It also explores key cutting, rekeying, master key systems, access control basics, door alignment, hardware troubleshooting, and the tools used in the trade. Beyond technical skills, the guide discusses service calls, customer communication, business fundamentals, safety practices, and career development, helping beginners understand how to grow from entry-level locksmith work into the broader role of a full physical security technician responsible for secure, reliable building access systems.