Commercial Lever Locks
Cylindrical locksets are the most common commercial locks used. This type takes the standard 161 lock prep which, as shown in the enlarged graphic, is a 2 1/8" crossbore, 2 3/4" backset, and a 2 1/4" x 1 1/8" square corner edge cut out in the door.
Mortise locks provide the highest level of security. They are built for heavy duty use, and are priced accordingly. You'll see these in a lot of public schools and Universities...but they are called for just about anywhere that expects to get heavy & frequent use...and abuse.
The prep for this lock is an 8" x 1 1/4" edge cut out in the door, with holes drilled in the face of the door at different locations depending on the lock function required. The lock body inserts into the edge prep so it is recessed into the door. The handles, cylinders, thumbturns, and/or escutcheon plates are then installed through the door face cut outs into the lock body. The enlarged graphic on the right provides a good look at what holes will be used for different functions.
The standard strike plate with commercial locks is the 497 ANSI strike which is a 4 7/8" ASA strike. The prep for it in the frames is shown below along with the strike plate...which comes with the lock. This is the strike plate that will come standard with most commercial locks, unless a 2 3/4" T-strike, a full lip strike, or something else is called for.
There are many different lock functions for whatever application you require but there are four types that are used most often.
Entry Function: This lock has a key on one side and a push button on the other. When the button is depressed, it can only be unlocked from the outside with a key. Turning the handle on the inside will cause the button to pop out, which unlocks the door until either the button is depressed again or it is locked from the outside with a key.
Storeroom Function: This lock has a key on one side and a blank handle on the other side (no key or button). It remains locked at all times from the outside and requires the key to open it every time you open the door. It is always unlocked from the inside. This is used on a lot of storage rooms, utility rooms, and janitor's closet.
Privacy Function: This lock has a push button on one side and an emergency release on the other side. It is made so that it can be locked from the inside but can be opened from the outside with a tool (usually a coin or screwdriver will do) in case of an emergency. These are used on a lot of bathrooms.
Passage Function: This has no key or push button on either side. It consists of two blank handles. Both sides are always unlocked. This is sometimes used on stairwell doors or any other doors where all you require is to have the door latch behind you but not lock so that it can be opened at all times.
Double cylinder deadbolts have a key on both sides while single cylinder deadbolts have a key on one side and a thumbturn on the other side. These locks take the standard 161 prep which is shown above in the Cylindrical Locksets section..