The following list shows different mechanical door lockset functions. Door hardware manufacturers may use various terminology, but these are standard terms. Refer to specific manufacture data prior to specifying types.
Locksets that require a key to retract the latch or deadbolt on the inside are not recommended for egress use.
The term "grip" below is used to refer to either the lever or knob. Most commercial and institutional mechanical locks use lever handles because they are more accessible. Knobs are generally reserved for residential, but that is also changing toward lever handles.
You may also be interested in our article that describes the difference between mortise locks, cylindrical locks, and unit locksets. It is also important for architects and specifiers to understand door handing so they can properly communicate to manufacturers which direction the door will swing.
Mechanical Locksets Without a Deadbolt
Classroom Lockset - The latchbolt is retracted by the grip on either side unless the outside grip is locked by the outside key.
Classroom Security Lockset - The latchbolt is retracted by the grip on either side unless the outside grip is locked by either the inside key or the outside key. Operating the inside grip always retracts the latchbolt.
Institutional (Asylum) Lockset - The latchbolt is retracted by a key on either side. The grips on both sides are rigid.
Office Lockset - The latchbolt is retracted by the grip on either side unless the outside grip is locked by the toggle or outside key. Operating the inside grip does not unlock the outside grip.
Passage Lockset - The latchbolt is always retracted by the grip on either side. Both grips are always free.
Privacy Lockset - The latchbolt is retracted by the grip on either side unless the outside grip is locked by the inside thumb-turn, button, or key. Operating the inside grip unlocks the outside grip. An emergency release tool unlocks the outside grip. Some manufacturers offer models that also unlock the outside grip when the door is closed (i.e. the door can only be locked from the inside if the door is fully closed - locking an open door then closing the door unlocks the outside grip).
Public Restroom Lockset - The latchbolt is retracted by the inside grip or an outside key. The latchbolt is retracted by the outside grip unless the grip is locked by a key from the inside. The latchbolt / outside grip cannot be locked by a key from the outside.
Storeroom Lockset - The latchbolt is retracted by the inside grip or outside key. The outside grip is optional, but when provided it is always rigid.
Mechanical Locksets With a Deadbolt
Apartment Lockset - The deadbolt is engaged or retracted by an outside key or an inside thumb-turn. When the deadbolt is engaged the outside grip is locked and will not retract the latchbolt. When the deadbolt is engaged the inside grip simultaneously retracts both the deadbolt and the latchbolt. The latchbolt alone can be locked by a toggle (engaging the deadbolt is not required to lock the outside grip).
Classroom Security Lockset - The deadbolt is engaged or retracted by key on either side. When the deadbolt is engaged the outside grip is locked and will not retract the latchbolt. When the deadbolt is engaged the inside grip simultaneously retracts both the deadbolt and the latchbolt and leaves the outside grip unlocked.
Dormitory Lockset -The deadbolt is engaged or retracted by an outside key or an inside thumb-turn. When the deadbolt is engaged the outside grip is locked and will not retract the latchbolt. The latchbolt is retracted by the grip on either side as long as the deadbolt is retracted. When the deadbolt is engaged the inside grip simultaneously retracts both the deadbolt and the latch.
Storeroom Lockset - The latchbolt is retracted by the grip on either side. The deadbolt is engaged or retracted by the outside key or the inside key / thumb-turn. The latch and deadbolt operate independently.
Store Door Lockset - The latchbolt is retracted by the grip on either side. The deadbolt is engaged or retracted by the key on either side. The latch and deadbolt operate independently.
Deadbolt Only
Deadlock - The deadbolt is engaged and retracted by an outside key. An optional inside key or thumb-turn will engage or retract deadbolt.
Classroom Deadlock - The deadbolt is engaged and retracted by an outside key. An inside thumb-turn will retract the deadbolt only (it will not engage the deadbolt). An optional inside key will engage the deadbolt.
Door Lock Grades
The United States standards for door locksets are maintained by the American National Standards Institute (ANSI) and the Builders Hardware Manufacturers Association (BHMA). ANSI/BHMA A156.2 covers cylindrical locksets while ANSI/BHMA A156.13 covers mortise locks.
Each standard has durability requirements rated from 1 to 3. Grade 1 locks are the most durable and secure - they must withstand 1,000,000 cycles of opening and closing. Grade 3 is the least durable and secure so they are the least expensive, but not recommended for use where security and longevity are important.
Regardless, be sure your lockset carries an ANSI/BHMA A156 label to ensure the lock will perform well.
