CPL Lock Installation & Maintenance 2

Question 1

When installing a cylindrical lockset, what is the standard backset measurement used in most US residential applications?

Accepted Answer

2-3/8 inches

Answer

The standard backset for most US residential cylindrical locksets is 2-3/8 inches, measured from the door edge to the center of the bore hole.

Question 2

Which tool is used to cut the edge bore hole for a cylindrical lockset installation?

Accepted Answer

Spade bit

Answer

A spade bit is typically used to drill the edge bore (latch hole) in the door edge for cylindrical lockset installation.

Question 3

What is the purpose of a 'strike box' installed behind a door strike plate?

Accepted Answer

To provide a cavity for the latch bolt to retract into the frame

Answer

A strike box provides a recessed cavity behind the strike plate that allows the latch bolt to fully retract, enabling smooth door operation.

Question 4

When installing a mortise lock, which measurement is critical for ensuring proper operation of the lock body within the door?

Accepted Answer

Mortise pocket depth

Answer

The mortise pocket depth must exactly match the lock body dimensions to ensure the lock sits flush and operates correctly within the door.

Question 5

What type of lubricant is recommended for maintaining pin tumbler lock cylinders?

Accepted Answer

Graphite powder or dry PTFE lubricant

Answer

Graphite powder or dry PTFE (Teflon) lubricant is recommended for pin tumbler cylinders because it does not attract dirt or gum up the mechanism.

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