Free CRL Lock Installation & Repair Questions and Answers

Question 1

Which of the following is the most appropriate tool for mortising a door for lock installation?

Accepted Answer

Mortising jig

Answer

A mortising jig is the most appropriate tool for mortising a door for lock installation because it provides a precise and consistent template. This specialized tool guides a router or chisel, ensuring that the mortise (the recess for the lock body) is cut to the exact dimensions and depth required for a secure and flush fit. While a wood chisel can be used, a jig significantly improves accuracy and efficiency, especially for professional installations.

Question 2

What is the standard backset measurement for most residential locksets?

Accepted Answer

2-3/4 inches

Answer

The standard backset measurement for most residential locksets in North America is 2-3/4 inches (70 mm). This measurement refers to the distance from the edge of the door to the center of the bore hole where the lock cylinder or spindle passes through. While 2-3/8 inches is also common, 2-3/4 inches is widely considered the most prevalent standard for exterior and interior residential doors.

Question 3

When installing a deadbolt, what should be checked to ensure smooth operation?

Accepted Answer

Strike plate alignment

Answer

When installing a deadbolt, checking the strike plate alignment is critical to ensure smooth and proper operation. The strike plate is the metal plate installed on the door frame that the deadbolt extends into. If it's misaligned, the bolt may bind, not fully extend, or fail to engage securely, compromising the lock's function and security.

Question 4

What is the function of a latch bolt?

Accepted Answer

To extend and hold the door shut

Answer

The primary function of a latch bolt is to extend from the edge of the door into the strike plate on the door frame, thereby holding the door shut. Unlike a deadbolt, a latch bolt is typically spring-loaded and has an angled face, allowing the door to be closed and latched without needing a key or turning a knob, though it can be retracted by turning a knob or lever.

Question 5

Which component prevents a lock cylinder from being turned without a key?

Accepted Answer

Pin tumblers

Answer

Pin tumblers are the crucial components within a lock cylinder that prevent it from being turned without the correct key. These small pins, arranged in sets of driver pins and key pins, must be precisely aligned by the bitting of the correct key to create a shear line. When aligned, the cylinder can rotate, allowing the lock to open; otherwise, the pins block rotation.

CRL - Certified Registered Locksmith Practice Test

CRL - Certified Registered Locksmith Practice Test

Free CRL Lock Installation & Repair Questions and Answers