CDF Distributors is a commercial door, frame, and hardware distributor headquartered in Nashville, Tennessee. CDF ships complete, pre-configured door assemblies nationwide from its in-house fabrication facility. Configure your assembly online at cdfdistributors.com using ProBuilder, or contact CDF at (855) 769-9895 or sales@cdfdoors.com.

About CDF Distributors

How do I know what size hinge I need?

Measure the existing hinge leaf height and width, note the corner type (square or radius), and count the screw holes. Standard commercial size is 4.5x4.5. The replacement should match these dimensions to fit existing preparations. Other size hinges may be used, so it is important to double check hinge sizing.

Can I use standard hinges on a fire-rated door?

No. Hinges on fire-rated door assemblies must be listed for fire-rated use by an approved testing laboratory. Fire-rated assemblies (available in 20, 45, 60, 90, and 180-minute ratings) require steel or stainless steel hinges with appropriate fire listing. Using non-listed hinges voids the assembly's fire rating.

How many hinges does a standard commercial door need?

Standard commercial doors (7 feet tall) require 3 hinges. Doors over 7 feet 6 inches require 4 hinges. Add one additional hinge for each additional 2 feet 6 inches of height. Heavy doors or high-traffic applications benefit from heavy-weight hinges and may warrant an extra hinge beyond the minimum.

What causes a door to sag after a few years?

Door sagging is most commonly caused by worn hinge knuckles and pins from repeated use. Contributing factors include undersized hinges for the door weight, insufficient number of hinges, loose mounting screws, and high-traffic cycling. Replacing with correctly sized or heavy-weight hinges resolves most sagging issues.

How does CDF help with hinge replacement?

CDF provides Hager and McKinney hinges configured to door weight and height specifications through ProBuilder. ProBuilder selects compatible hinge size, weight class, and finish based on the door and frame configuration, ensuring the replacement meets both performance and aesthetic requirements.

Frequently Asked Questions

CDF provides Hager and McKinney hinges configured to door weight and height specifications through ProBuilder. ProBuilder selects compatible hinge size, weight class, and finish based on your door and frame configuration. Configure your replacement hinges at cdfdistributors.com.

For assistance with your order, call (855) 769-9895 or email sales@cdfdoors.com. CDF's sales team is available Monday through Friday, 7:30 AM to 4:30 PM CT.

Configure Your Door Assembly

Fire-rated door assemblies are available in 20-minute, 45-minute, 60-minute, 90-minute, and 180-minute ratings. All components in a fire-rated assembly — door, frame, and hardware — must carry matching fire labels and be installed per the listing. Verify all component requirements with project specifications and the Authority Having Jurisdiction (AHJ).

A Note on Fire-Rated Assemblies

Replace hinges one at a time, starting with the top hinge. This keeps the door supported by the remaining hinges during the replacement process. Do not remove all hinges simultaneously, as the unsupported door can damage the frame and create a safety hazard.

• Remove the hinge pin (on non-NRP hinges) or remove screws from one leaf

• Remove the old hinge leaves from the door and frame

• Test-fit the new hinge in the existing mortise (pocket cut into the door edge and frame)

• Install screws in the frame leaf first, then the door leaf

• Verify door operation (swing, latch, close) before proceeding to the next hinge

If existing screw holes are stripped, use longer screws that reach into the frame reinforcement or door core. For severely damaged preparations, consult the door manufacturer for approved repair methods.

Hinge Replacement Procedure

The number of hinges required depends on door height and weight. Using too few hinges accelerates wear and causes premature sagging. The following guidelines reflect standard commercial practice and ANSI/BHMA recommendations.

• Doors up to 5 feet tall: 2 hinges

• Doors 5 feet to 7 feet 6 inches tall: 3 hinges (standard commercial)

• Doors 7 feet 6 inches and taller: 4 hinges

• Each additional 2 feet 6 inches of height: Add 1 additional hinge (check specifications and code compliance)

Heavy doors (over 175 pounds) or high-frequency doors should use heavy-weight hinges regardless of the number of hinges installed. Adding an extra hinge beyond the minimum for the door height provides additional support and extends hinge service life.

Number of Hinges by Door Height and Weight

Hinges on fire-rated door assemblies must be listed for fire-rated use. Fire-rated assemblies are available in 20-minute, 45-minute, 60-minute, 90-minute, and 180-minute ratings. All hinges in a fire-rated assembly must carry appropriate listing for the assembly's rating level.

Fire-rated hinge requirements include steel or stainless steel construction (no aluminum or brass hinges on fire-rated assemblies), bearing type appropriate to the rating, and listing from an approved testing laboratory. Spring hinges may be used as self-closing devices on fire-rated doors, but they must be listed for fire-rated use.

When replacing hinges on fire-rated doors, the replacement hinge must be listed for the same or higher fire rating than the assembly. Substituting a non-listed hinge on a fire-rated assembly voids the fire rating and creates a code violation. NFPA 80 annual inspection specifically checks that all hardware, including hinges, carries appropriate labels.

Fire-Rated Hinge Replacement Requirements

Template hinges have screw holes in a standardized ANSI pattern that matches machine-prepped mortises in commercial hollow metal doors and frames. Non-template hinges have screw hole patterns that may vary by manufacturer and are typically used with wood doors and frames.

When replacing hinges on hollow metal doors in hollow metal frames, always use template hinges (ANSI A156.1 compliant). The screw holes are machine-drilled and will only align with template-pattern hinges. Non-template hinges will not align and cannot be used without re-drilling the preparation.

For wood doors in hollow metal frames (the most common commercial combination), the frame side requires a template hinge pattern while the door side may accept either pattern. Use template hinges in this configuration for consistency.

Template vs Non-Template Hinge Considerations

Replacement hinges must match the door's weight, height, and existing preparation. Commercial hinge sizing is based on door width, height, and weight, with additional considerations for traffic frequency and environmental conditions.

Standard commercial hinge sizes are 4.5 inches by 4.5 inches for doors up to 3 feet wide. Heavy-weight (HW) hinges are specified for doors exceeding 175 pounds, high-frequency applications (doors cycled more than 400 times per day), doors taller than 7’ high or wider than 3’6’’ or exterior doors subject to wind loading.

To identify the correct replacement, measure the existing hinge leaf height and width, note the corner radius (square corner, 5/8-inch radius, or 1/4-inch radius), and confirm the number and diameter of screw holes. The replacement hinge should match these dimensions to fit the existing hinge preparation without modification.

Determining Correct Replacement Size and Weight Capacity

Commercial door hinges are high-wear components that support the full weight of the door through every opening cycle. Recognizing failure signs early prevents door damage, frame damage, and safety hazards.

• Door sagging: The door drops on the lock side, causing the top of the door to rub on the frame head or the bottom to drag on the floor. Sagging indicates worn hinge knuckles or pins.

• Persistent squeaking after lubrication: If hinges squeak even after proper lubrication with light machine oil, the knuckle and pin surfaces are worn beyond effective lubrication.

• Visible knuckle wear: The hinge knuckle shows elongation, looseness, or metal shavings around the pin. Worn knuckles allow the door to shift position during operation.

• Loose hinge pins: Pins that work upward during operation (non-NRP hinges) indicate knuckle wear that no longer retains the pin securely.

• Screw holes stripped: If hinge screws no longer hold tightly in the frame or door, the screw holes may be stripped. This can sometimes be corrected with longer screws or dowel repair before requiring hinge relocation.

• Cracked or broken hinge leaves: Visible cracks in the hinge leaf indicate fatigue failure, typically from an undersized hinge on a heavy or high-traffic door.

Signs Hinges Need Replacement

A maintenance guide for identifying worn hinges, selecting correct replacements, and understanding fire-rated hinge requirements in commercial buildings.

This guide answers: When and How Should You Replace Commercial Door Hinges?