The 4-1-1 On Hinges

There are four basic types of standard hinges: full mortise, half mortise, full surface and half surface.

The Four Types of Hinges

An illustration showing how a full mortise hinge works with a door frame and door

The full mortise hinge is the most frequently used type of hinge today. It can be used on aluminum, hollow metal and wood doors and frames. It was formerly referred to as a “butt hinge” because the two leaves of the hinge are pressed together when the hinge is closed. It is used for medium to heavy weight doors that are subjected to low to high frequency use. When the door is closed, the barrel is the only part of the hinge that is visible.

An illustration showing how a half mortise hinge works with a door frame and door

The half mortise hinge is generally used on hollow metal doors with channel iron frames that experience medium to high frequency use.

An illustration showing how a full surface hinge works with a door frame and door

The full surface hinge is for medium weight tubular steel doors and kalamein wood doors with channel iron frames under medium to high frequency service

An illustration showing how a half surface hinge works with a door frame and door

The half surface hinge is for regular weight hollow metal or wood composite doors with hollow metal frames that see medium to high frequency use.

Special Hinges

There are also some special types of hinges sometimes used with emergency exit doors. One of these is the continuous hinge, also called a continuous geared hinge or a traditional piano hinge. This hinge distributes the weight of the door along the full height of the door frame, and allows smooth operation and longer life for the door opening. Continuous hinges are great options on all openings, but especially high-use doors. And adding full length continuous hinges to exterior doors means that an intruder must cut the hinge the entire length of the door, which, while possible, requires much more time and effort.

An illustration showing how a swing clear hinge works with a door frame and door, both open and closed

Another special type of hinge is the swing clear hinge. Swing clear hinges are generally used on ADA swing doors, since they are designed to swing completely clear of the frame when opened, which creates a wider opening for maximum access.

electric hinge

An electric hinge is a special type of hinge that allows electrical current to pass from a door frame to a door. This allows the use of electronic hardware on doors, such as electric locks, electrified exit devices, access control systems, or monitoring devices without use of visible wiring.

There are also specific hinges for security applications of emergency exit doors.

Choosing A Hinge

There are a few factors that should be considered when choosing which type of hinge should be used, including the weight of the door, the frequency of use and the environment. Obviously, the correct choice of hinge depends on the application.

Interior doors usually have two hinges, while heavier exterior doors usually have three.

Concealed hinges are used when the design mandates that the hinge not be visible. A knuckle hinge is the exact opposite of a concealed hinge, in that it is intended to be seen and admired.

High-use doors, such as employee entrances and main entrances, might require heavy weight, ball bearing hinges in a finish that can endure the weather and elements. Bearings offer the highest levels of durability and ease of operation.

Medium-use doors, such as trash removal or receiving doors, might require a medium weight, standard 5-knuckle hinge in a durable finish.

Light-duty doors, such as emergency exit doors, may require three or even four hinges.

To help ensure the door provides trouble free operation, the height, width and weight of the door should be considered when choosing the type of hinge and the number of hinges.

Understanding Power Transfers: A Guide to Wiring Electrified Doors

When it comes to electrified locks and exit devices, power transfers play a crucial role in ensuring seamless operation while maintaining security and aesthetics. Whether you’re planning new construction or retrofitting existing doors, selecting the right power transfer solution can make all the difference.

What Are Power Transfers?

Power transfers provide a means of running wires from the door frame to electrified door hardware such as locks, strikes, or exit devices. They come in various forms, each suited to specific applications and installation requirements.

Types of Power Transfers

  1. Surface-Mounted Power Transfers
    • Includes armored door cords or door loops.
    • Economical and easy to install on existing openings.
    • Ideal for field preparation in both retrofits and new construction.
    • Highly visible but durable, making them a practical choice for many applications.
  2. Concealed Power Transfers
    • Mortised into the door and frame for a clean, tamper-resistant installation.
    • Factory-prepared and approved for fire-rated openings.
    • Best for heavy-traffic environments or areas requiring higher security.
  3. Electric Hinges
    • Provide a concealed and vandal-resistant method of running wires.
    • Fit into standard 4-1/2″ or 5″ hinge preparations with minor modifications for wire clearance.
    • Recommended for the center hinge position for optimal performance.
  4. Wireless Power Transfers
    • Use radio frequency (RF) transmitters to wirelessly transfer energy across the door gap.
    • Eliminate the need for drilling or conduit installation, making them ideal for retrofits, especially with wood doors.
    • Capable of transferring power and signals, including latch bolt monitoring and request-to-exit (REX) signals.

When Are Conduits Needed?

  • For electrical locks and strikes, a conduit or raceway is often recommended to run wires from the hinge-side preparation to the lock or strike preparation.
  • With electrical panic devices, most connections are through the hinge-side mounting, and no conduit is typically required in the door.

Benefits of Power Transfers

  • Aesthetic Appeal: Concealed power transfers maintain a clean look by hiding wires.
  • Durability: Heavy-duty options are designed to withstand frequent use in high-traffic areas.
  • Security: Concealed solutions reduce the risk of tampering or vandalism.
  • Ease of Installation: Surface-mounted and wireless options simplify retrofitting and field preparation.

Key Considerations

  • Always consult your Authority Having Jurisdiction (AHJ) to ensure compliance with fire-rated opening requirements.
  • For high-security or heavy-traffic environments, prioritize concealed or heavy-duty power transfers to enhance durability and tamper resistance.
  • For retrofits, consider wireless options to save time and avoid invasive installations.

Conclusion

Power transfers are the unsung heroes of electrified door systems, ensuring reliable power delivery while maintaining security and aesthetics. By understanding the types and applications of power transfers, you can choose the right solution for your project, whether it’s a high-security facility, a retrofit, or a new construction.

For more information or assistance with selecting the ideal power transfer for your needs, feel free to reach out to our team.