CML Cheat Sheet 2026

The 30 highest-yield CML facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Which wiring configuration allows monitoring of a door contact's open, closed, and tampered (wire cut) states? → Supervised circuit with end-of-line resistors
2. What role does calibration play in maintaining technical accuracy for Certified Master Locksmith professionals? → It ensures instruments produce accurate, consistent results over time
3. What is a master key system? → Key that opens multiple locks
4. Why is regular maintenance important for security systems? → Ensure reliable function and detection
5. What is the importance of honesty in business dealings? → Build trust and relationships
6. When drilling a safe, which area is typically targeted to bypass the combination lock? → The drill point above the dial to access the lock lever pack
7. What is the PROPER procedure for decommissioning outdated equipment in Certified Master Locksmith? → Follow established protocols for safe decommissioning, data clearing, and proper disposal
8. When servicing a Sergeant & Greenleaf (S&G) three-wheel combination lock, what is the standard method to set a new combination? → Use the change key inserted in the back of the lock to set each wheel's gate position
9. Why is professional ethics important in locksmithing? → Build trust and reputation
10. What is the role of professional associations for locksmiths? → Offer education and standards
11. Which factor MOST significantly affects the quality of technical outcomes in CML practice? → The practitioner's training, preparation, and attention to detail
12. What is the first step a CML technician should take when a customer reports a safe with an unknown combination? → Verify ownership documentation before attempting any entry
13. After drilling a safe and completing repairs, a CML should: → Plug the drill hole with a hardened steel insert and document the service
14. How should Certified Master Locksmith professionals handle procedures that have been updated or revised? → Review updates, complete required training, and implement revised procedures
15. Which document published by ASIS International provides guidelines for performing physical security assessments? → ANSI/ASIS PSC.1
16. How should Certified Master Locksmith professionals handle procedures that have been updated or revised? → Review updates, complete required training, and implement revised procedures
17. Which type of key system offers the highest security? → Restricted key system
18. What does 'all keys lost' mean for a modern transponder-equipped vehicle? → All programmed transponder codes must be erased and new keys programmed from scratch
19. When conducting a risk assessment for CML operations, which factor should receive the HIGHEST priority? → Probability and severity of potential harm
20. Why is key control important in locksmithing? → Prevent unauthorized duplication
21. How should locksmiths handle confidential information? → Protect from unauthorized access
22. Which type of credential provides the HIGHEST security against cloning attacks in modern access control? → 13.56 MHz smart cards with mutual authentication (e.g., MIFARE DESFire)
23. How does wireless technology benefit security systems? → Enables flexible installation
24. What is the purpose of a 'day gate' feature found on some high-security combination locks? → Enables the safe to open with only a partial combination rotation for quick daytime access
25. What is the FIRST step before operating any equipment in CML practice? → Conduct a pre-operation inspection and verify safety systems
26. What is a master key hierarchy? → Higher-level keys open multiple locks
27. What documentation does ALOA professional standards require for automotive key origination jobs? → A record of the customer's ID, vehicle information, and work performed
28. When a CML professional encounters an unexpected result during a procedure, the FIRST action should be to: → Stop, assess the situation, and determine whether to proceed or seek guidance
29. During a security survey, a locksmith finds a hollow-core door protecting a server room. The most appropriate recommendation is to: → Replace it with a solid-core or hollow-metal door
30. What distinguishes a Certified Master Locksmith certified professional from a non-certified practitioner? → Certification validates competency through standardized assessment against benchmarks