Did you ever think why your door key opens only your lock, and each of your neighbors' keys opens only each of theirs -- but the superintendent can open everyone's locks? How many keys does he carry anyway? The key to this question is in this quiz.
If a large apartment building has a hundred apartments, how many keys does the superintendent need to open the doors?
none because the owners have their own keys
What is the most common lock design?
What happens when you turn the cylinder in a cylinder lock?
It turns a cam.
It turns a plug.
It turns a spring.
Using the correct key to open a cylinder lock is comparable to:
stringing together a string of beads
conducting a wrestling match
solving a puzzle
What are the main components of a pin and tumbler lock?
small metal pins
tiny, metal, tumbler-looking receptacles
neither of the above
How are the pins grouped together?
they're not grouped; they fit singly in the unit
What keeps the plug from turning?
the position of the bottom pins
the position of the upper pins
the housing unit
What is meant by the term, the shear line?
You insert a key into a lock and the key is aligned with the two sides of the lock.
The right key is put into the lock and the pins line up perfectly.
A master key that can open any door "shears" against the pins.
In locks of a specific group that can be opened by a master, some pin pairs are separated by a third pin. What is this third pin called?
both of the above
A master key raises the pins in the lock so that the shear line is at the bottom of the wafer. What is at the shear line that enables the key to turn?