When shopping for new door locks, the three
factors to consider are security, style,
and appearance. We'll discuss the first two
and only say that appearance is a matter
of taste but that the look should match the
appearance (both in material, such as brass
or aluminum, and design) of the other hardware
and styles in the room.
The purpose of a lock is to keep others out.
The strength of the door lock you need depends
on the level of security you seek. For many
people, a simple lock is sufficient because
they just want to prevent a crime of opportunity.
For others, they are seeking a whole security
system that makes their home, if not impenetrable,
at least very hard and time consuming to
break into. As you would expect, it costs
considerably more to provide higher levels
of security through devices that resist picking
and forcing, so choose the level with which
you are comfortable.
Locks come in single or double cylinder styles.
Double cylinder models require a key to open
the lock from either side; the single models
have a knob on the inside. For the home,
the single cylinder style is highly preferable
because it prevents trapping someone without
the key at hand inside in case of a fire
Doors use either a latch bolt or a deadbolt.
Latch bolt locks are designed so that the
lock can be engaged before the door is pulled
shut. The angled surface of the spring-loaded
latch bolt causes the latch bolt to retract
when it contacts the "strike plate"
on the door frame. However, this style is
susceptible to jimmying since the latch is
not immovable even though the lock is engaged.
Deadbeats must be manually thrown (either
by the inside knob or by a key). Deadbolts
provide a higher level of security and reduced
likelihood of lock outs (since from the outside
you must use your key to lock the door).
Most doors are equipped with
a latch bolt
because it is easy to latch the
by pulling it. If the door is
lock is generally integrated
into the knob
and controls the ability of the
knob to turn
and disengage the latch. A second
a deadbolt) is added to the door
security. The second latch can
in a mortise style lock (with
the latch and
deadbolt part of a single, internal
or a separate lock attached to
surface of the door and the door
a "rim" or "drop"