From the most basic entry lockset to a keyless entry system equipped with an alarm, security door locks are as varied as the types of security needed. Entry locksets are the most basic type of security door locks, including a relatively simple lock in the door handle; this type is often seen in residential applications. One of the more common choices for added security is a deadbolt lock. Handle sets combine a entry lockset with a deadbolt.
Spring-operated entry locksets offer a minimal amount of security, but are convenient. Typically, there is a push-button on the interior side of the door handle, and a key access on the exterior. The door can be locked from either side. Some entry locksets have key access on both sides.
Deadbolts provide a high-level of security, and they come in several different styles. The name, deadbolt, refers to the manual operation of the lock, as there are no springs used to operate it. A single-cylinder lock uses a key on one side and a hand-turned knob on the other, while a double-cylinder uses a key for each side. Surface-mounted deadbolts, which mount to the inside surface of a door, are another deadbolt type of security door lock.
Many people choose a combination of home security door locks, using sets that combine an entry lockset with a deadbolt. The entry lockset is often more for appearance than security; the deadbolt provides the defense. Many manufacturers sell these sets with the deadbolt and the lockset keyed the same. This allows one key to operate both locks.
Mortise locks, so named for the pockets or mortises cut into the door, operate similar to a deadbolt. When used the conjunction with a metal door, this type of door lock can provide a great amount of security. The labor-intensive nature of this lock means that it requires a professional installation, however. Although it's sometimes seen on large entryway doors, the mortise lock is not often used on residential doors.
Keyless entry systems often use electronic keypads in place of traditional keys. Many systems are set up with alarms addition to window and security door locks. The alarm systems can be either sound and light deterrents or contact a security company in the event of a breach. These types of security door locks often used deadbolts to secure the doors.
Other safety features of some security door locks include deadbolts with a minimum of a 1-inch (2.54-cm) throw and internal anti-saw pins. The throw is the length past the edge of the door that the deadbolt extends. Hardened steel chips will prevent a lock from being drilled out. Hardened steel casings and high-security strike plates both increase the effectiveness of a security door lock. Key-controlled locks prevent unauthorized copying of your door lock keys.