CPL Exam Practice Questions And

ALOA Certified Professional Locksmith (CPL) Exam Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• Which type of key is most commonly used for residential pin-tumbler

locks?

• Tubular key
• Skeleton key
• Standard pin-tumbler key
• Double-bit key

Rationale: Standard pin-tumbler keys are the most common for

residential locks, fitting the pin configurations.

• What is the primary function of a master key system?
• To duplicate keys quickly 1 / 4

• To bypass security systems
• To allow multiple locks to be operated by a single key
• To restrict access to locksmiths only

Rationale: Master key systems are designed to allow a single key to

operate multiple locks while maintaining individual keys for each lock.

• Which tool is used to tension a lock when picking a cylinder?
• Pinning kit
• Plug spinner
• Tension wrench
• Key decoder

Rationale: The tension wrench applies rotational pressure to the

plug, allowing pins to be set when picking a lock.

• What is the difference between a wafer lock and a pin-tumbler lock?
• Wafer locks are only used in safes
• Wafer locks use flat wafers instead of pins
• Pin-tumbler locks cannot be rekeyed
• Wafer locks cannot use master keying

Rationale: Wafer locks use flat wafers arranged in the plug, while

pin-tumbler locks use pins of varying lengths.

• What is the primary purpose of a lock’s deadbolt?
• To provide automatic locking
• To provide additional security beyond the latch bolt 2 / 4

• To prevent key duplication
• To restrict padlock use

Rationale: Deadbolts extend fully into the door frame, offering

stronger protection against forced entry than latch bolts.

• When rekeying a cylinder, what must be done first?
• Insert new springs
• Remove the plug from the cylinder housing
• File down pins
• Lubricate the cylinder

Rationale: The plug must be removed from the cylinder housing to

access pins and springs for rekeying.

• Which type of lock is commonly used in safes for high-security

applications?

• Pin-tumbler lock
• Mortise lock
• Wafer lock
• Combination lock

Rationale: Combination locks are often used in safes because they

offer high security without requiring a key.

• What is the purpose of a lock’s sidebar in certain high-security locks?
• To allow easy key duplication
• To provide additional security by blocking plug rotation unless

aligned 3 / 4

• To lubricate the pins
• To act as a decorative element

Rationale: Sidebars are security features that prevent plug rotation

unless the key aligns internal mechanisms correctly.

• Which tool is used to decode a key by measuring cuts on an existing

key?

• Tension wrench
• Plug follower
• Key gauge or key decoder
• Pinning tray

Rationale: Key decoders measure cuts on a key to determine the

corresponding pin sizes.

• What type of keyway is designed to prevent unauthorized

duplication?

• Standard keyway
• Restricted or patented keyway
• Oval keyway
• Skeleton keyway

Rationale: Restricted keyways require authorization or specific

tooling to duplicate, enhancing security.

• Which of the following is NOT part of a typical pin-tumbler lock?
• Springs
• Pins
• / 4