There is little doubt that the dead bolt is the most secure kind of lock. Unlike latching locks that latch automatically when a door closes, a dead-bolt lock must be intentionally locked. The dead bolt cannot be easily kicked, sprung, or manipulated with a credit card or hand-tools like latching locks. Electrified dead bolts allow for manual remote release or operation by an Electronic Access Control System (Figure 12.1).

The simplest kind of dead bolt is the Surface-mounted Electrified Dead-Bolt Lock. This comprises a solenoid or motor operated dead bolt, a receiver, and enclosures for both. The lock is typically mounted to the door frame and the receiver is surface mounted on the door. This lock should only be used on unoccupied rooms and never on fire exit doors.

For a more elegant installation, and one where the designer wants to ensure that the door locks when the door is closed, Concealed Direct-Throw Mortise Dead-Bolt Locks (Figure 12.2) are a good choice. Like the Surface-mounted version discussed earlier, the Concealed version includes a solenoid or motor-operated dead-bolt lock and a receiver. But that is where the similarity ends. The Concealed Direct-Throw Mortise Dead-Bolt Lock is mounted into the door frame and the bolt extends into a receiver pocket mounted into the door.

Typically, the dead bolt is equipped with a nylon sleeve to allow it to move smoothly without binding. Often the dead bolt is also equipped with a magnet at its tip, and there is an opposing magnet in the receiver pocket to repel the dead bolt in case the solenoid or motor needs help. To ensure that the lock re-locks automatically when the door closes, some of these locks are also equipped with a ball-switch in the body of the lock that engages a flat face on the lock receiver when the door closes. This action pushes the ball-switch in, energizing the lock to ensure that it does not extend again until the door is closed again. This also enables automatic re-locking on door closure.

Like its surface-mounted cousin, this lock should never be used on an occupied room. Its application is appropriate for storage rooms only.

With all this talk about Electrified Dead-Bolt Locks not being useful on occupied rooms, wouldn't it be good to hear about one that is legal for occupied rooms? Well, there are a few available and the most basic is the Dead-Bolt Equipped Electrified Mortise Lock (Figure 12.3).

Imagine an Electrified Mortise Lock to which a dead bolt has been added. Several manufacturers make such a lock. In most cases, the dead bolt is not operated by an electrical mechanism. For most such locks, the operation of the dead bolt is semi-mechanical.

In this lock, the latch set of the lock operates like a normal electrified mortise lock with its dead bolt retracted by an electrical signal. However, for most such locks the dead bolt cannot be thrown to a locked position electrically.

It is possible to electrify Panic Hardware with Concealed Vertical Rods to allow for their remote or timer release or release by an Electronic Access Control System. Security Door Controls (SDC) manufactures a lock called the Top-Latch Release Bolt (Figure 12.4), which is used to control entry from the outside only (remember, there is always free mechanical egress on Panic Bar equipped doors). On Panic Hardware doors equipped with Concealed Vertical Rods, the rods at the top rail are designed to engage a mechanical latch built into the frame header. SDC replaces this latch with a solenoid-operated latch release, allowing it to be electrically operated to permit entry from the outside.

The lock is also equipped with a ball-switch to hold the lock open until the door is re-closed, enabling an automatic re-lock function. The Top-Latch Release Bolt should generally be used on doors having vertical rods on the top only.

Electrified Dead-Bolt Gate Locks (Figure 12.5) work exactly like Surface-mounted Electrified Dead-Bolt Locks. However, they are more robust and resistant to weather, dirt, and water than their indoor-rated cousins.

Electrified Dead-Bolt Gate Locks should not be used on pedestrian gates that are in the path of egress.