Door Hardware 101
This primer will help you determine which locks, card access systems and other door devices are appropriate for your campus and district.
With increased interest in school safety, many K-12 administrators are more involved in the details of school security systems. While much discussion is on topics such as funding, lockdowns and other security and safety issues, access control is understandably also now a topic of keen interest.
Access control, in whatever its form, begins with door hardware, and it has its own nomenclature that can be confusing to administrators who are new to security. Thus, welcome to the world of mortise locks, strikes and dogging.
Here’s a breakdown of the various door hardware components, including credentials, strikes, locks, exit devices, door closers, automatic openers and accessories.
Credentials: Keys, Cards and Biometrics
Credentials are what you hold in your hand — or can even be your hand or finger — and are used to open a door. Although the best known and most widely used credential is the common key, keys are easily duplicated. If lost, locks need to be rekeyed and new keys issued. Because a lost key can be costly to a district, many schools have adopted key management systems.
Want to see examples of locks and door hardware? Check out our Door Hardware 101 photo gallery!
With a patent-protected key management system, keys are only available to authorized individuals through professional locksmith channels, which helps prevent unauthorized key duplication. It also helps convey to staff members the importance of accounting for keys.
To avoid the costs of keys, many schools now use access control cards. Magnetic stripe cards are the least secure, proximity cards provide mid-level security and smart cards are the most secure because they are the most difficult access control card to duplicate. Unlike keys, if a card is lost, its number is simply erased from the computer and the user is given a new card with a new number.
A biometric reader uses part of your body as the identifier. For example, with hand geometry, you lay your hand on a reader and, if your hand matches the template that was created when you enrolled, the door unlocks and you are admitted. Biometrics provides the highest level of security and greatest convenience as people always have their hands with them.
While keys fit into locks, an access control card or biometric needs a reader. That reader is typically next to a door. In some cases, the lock mechanism and reader are all in one unit (more on that later). Ultimately, everyone who uses access control cards will use smart cards because they cost approximately the same as the other cards, are much more secure, and they can also be used for cafeteria privileges, sporting event admittance, library privileges and other applications. If you are purchasing a card reader, make sure it is a multi-technology reader that reads all types of cards (mag stripe, proximity and smart) so that you don’t have to pull them out and install new readers once you switch to smart cards.
There are two types of strikes: mechanical and electronic. A mechanical strike plate is a metal plate affixed to a door jamb with one or more holes for the bolt of the door. When the door is closed, the bolt extends into the hole in the strike plate and holds the door closed.
An electronic strike does the same thing except that its surface can, upon command, pivot out of the way of the latch, letting the door be pushed open from the outside without any operation of the knob or lever. While activated, the knob or lever can be turned to allow a person or persons to leave from a secured area.
Because of this, an electronic strike offers more flexibility. Lockdowns are faster and, in times of crises, students can leave the classroom but the intruder can’t enter. Electric strikes are used as parts of many electronic access control systems to provide added security and conveniences such as traffic control and remote release.
Mechanical locks come in four variations: mortise, cylinder, spring bolt and deadbolt. Let’s look at the pros and cons.
Mortise: A mortise lock requires a pocket — the mortise — to be cut into the door into which the lock is to be fitted. Included are the lock body (the part installed inside the mortise cut-out in the door); the lock trim (which may be selected from any number of designs of doorknobs, levers, handle sets and pulls); the strike plate; and the keyed cylinder, which operates the locking/unlocking function of the lock body.