CRL Lock Installation & Repair

Question 1

What is the commonly recommended minimum bolt throw for a residential deadbolt?

Accepted Answer

1 inch

Answer

A 1-inch throw resists spreading and prying far better than shorter bolts.

Question 2

Which upgrade most improves a door jamb's resistance to kick-ins?

Accepted Answer

Longer strike plate screws into the framing stud

Answer

3-inch screws anchor the strike into the wall stud rather than just the thin jamb.

Question 3

What are the two standard backset dimensions for residential bored locks?

Accepted Answer

2-3/8" and 2-3/4"

Answer

Backset is measured from door edge to bore center, and 2-3/8" and 2-3/4" are the standard sizes.

Question 4

What are the standard hole sizes for a cylindrical lock installation?

Accepted Answer

2-1/8" cross bore and 1" edge bore

Answer

Standard prep is a 2-1/8" face bore and a 1" edge bore for the latch.

Question 5

A deadbolt binds only when the door is closed in humid weather; what is the most likely cause?

Accepted Answer

Door swelling or misalignment between bolt and strike

Answer

Swelling shifts the door so the bolt rubs the strike hole edge.

CRL - Certified Registered Locksmith Practice Test