A lockset’s function determines what steps must be taken to secure, unlock and
open a door secured by that lockset.
This may necessitate the use of a key to retract a latch each time one
wishes to gain access, or it may only necessitate the rotation of a lever or
knob. This article will cover the most
common lockset functions found on cylindrical lever and knob locksets on the
market today.
Converting
a lockset’s function requires replacing internal parts, which can be expensive. Some manufacturers may not have replacement
parts readily available so replacement of the entire lockset can sometimes
actually be more affordable. Therefore,
it is important that you select the proper lockset when you develop your
initial security plan. For this reason,
I will also be providing examples of where you will most likely encounter these
locksets. Below I have compiled a list
of the five most common types of cylindrical lock you will likely encounter. Next to the name of each function is the
corresponding code developed by the American National Standards Institute
(ANSI):
Passage Latch (F75): Rotation of either the inside or outside handle
retracts the latch bolt. No key is
required. This type of a lockset is only
used to keep a door closed and not intended in any way to secure an area. It is generally used in conjunction with a
latch bolt that does not deadlock, as loiding would not be a concern
Privacy Latch (F76): In the center of the inside handle is a
button. When pushed in, the outside handle
becomes locked. The outside handle may
be unlocked either by rotating the inside handle or by inserting a small
screwdriver or emergency key universal to that lock’s model (e.g. all Schlage
AL40S levers can be opened using the 35-250 privacy key). This lock is commonly found on restrooms and
areas where one is protecting themselves against someone inadvertently walking
in. It should not be used to secure property against theft. Closing the door will typically cause the
inside button to pop out, preventing a lockout.
This type of lock is commonly sold with a latch bolt that does not
deadlock
Classroom Lock (F84): Rotation of the inside handle will always
retract the latch bolt, allowing for egress at all times. On the outside handle is a keyed
cylinder. Rotation of the key 360
degrees clockwise will unlock the outside handle and allow for the removal of
the key. Rotation of the key 360 degrees
counterclockwise will lock the outside handle and also allow for the removal of
the key. This type of lock is sold with
a deadlatch to keep the lock from being loided.
There is no button or thumb turn on the inside handle. Therefore, if the door is unlocked one must
have the key in order to secure it. This
lock is commonly found in schools and universities where students may try to
lock their instructor out of the classroom, hence the name for this function
Storeroom Lock (F86): Rotation of the inside handle will always
retract the latch bolt, allowing for egress at all times. On the outside handle is a keyed
cylinder. Rotating the key will retract
the latch bolt temporarily, allowing the door to be pulled open. The outside handle cannot be used to retract
the latch bolt at any time and only exists to pull the door open or closed. This type of lock is sold with a deadlatch to
keep the lock from being loided. This
lock is commonly found paired with an electric strike on access controlled
doors. Users would gain entry through
the use of an access credential, such as a keycard, and then the door locks
behind them after they enter. The keyed
cylinder mostly acts as an emergency override in the event of panel or strike
failure. This type of lockset alleviates
any concern a client may have about their door being left unlocked
 |
| Entrance lock, inside view. Notice the button/thumbturn |
Entrance Lock (F109): On the inside handle is a button/thumbturn. Pushing the button in will lock the outside handle. On the
outside handle is a keyed cylinder. When
the lock is in this condition, rotating either the key or inside handle will
retract the latch bolt and cause the inside button to pop out, unlocking the
outside handle. If the button thumbturn
is pushed in, then rotated 90 degrees clockwise, rotating the key or inside
handle will retract the latch bolt, but it will not unlock the outside
handle. To unlock the outside handle,
turn the thumbturn 90 degrees counterclockwise, then rotate the inside handle. This type of lock is sold with a deadlatch to
keep the lock from being loided. You
will find this lock on individual working or living areas such as offices or
apartments where there is little concern about someone maliciously locking
others out and where a user may wish to leave their area unlocked temporarily
Not all locks on the market conform to
the ANSI standards, but many do. Knowing
what the common lock functions are will allow you to be better prepared as a
consumer and know what options you may have.
