Most security experts agree that a
single outer door lock will not provide adequate protection. For
example, any tumbler-type lock with an opening for a key also
provides an opening large enough for the lock to be picked. Thus, a
combination of two different types of locks are recommended. Here
are the most common types of locks used in the home:
Spring Latch Locks: A popular and
convenient lock that snaps closed whenever the bevelled latch seats
into a striker plate is the spring-latch lock. However, this lock
can be easily forced by inserting through the door frame a thin blade
or stiff plastic between the latch and the strike plate. Thus, a
spring lock should always be augmented by a second lock of a
different type.