Ball Bearing Hinges for Commercial Doors

When ball bearing hinges are needed

Plain bearing hinges rely on metal rubbing on metal at the knuckles. That is fine for light residential and low-use doors. Commercial doors with closers cycle constantly and carry the closer's force, so the knuckles wear quickly without bearings.

• Any door with a door closer.
• Heavy doors, wide doors and high-frequency doors.
• Fire-rated doors, where the listing calls for hinges of a certain type and material.
• Doors with electrified hardware, where an electric hinge with bearings carries power to the door.

Hinges are covered by ANSI/BHMA A156.1 (butts and hinges). Standard weight and heavy weight versions exist; heavy weight is the usual choice for high-traffic and heavy doors.

How many hinges does a door need

The common rule is one hinge per 30 inches of door height, or fraction of it. Wide or heavy doors may need more; check the hinge manufacturer's guidance.

Hinge sizes by door thickness and width

Hinge height is chosen by door thickness and width. Hinge width (the open dimension) is chosen so the door clears the trim and the frame when it swings open.

Most commercial hollow metal and wood doors are 1-3/4 inch thick and 36 inches wide or less, which is why 4-1/2 by 4-1/2 inch hinges are so common.

Standard weight vs heavy weight

Butt hinges come in standard weight and heavy weight versions. Heavy weight hinges use thicker leaves and a larger knuckle, so they resist bending and wear under heavy doors and constant use. Standard weight is fine for lighter, low-traffic interior doors.

Hinge manufacturers publish weight and frequency guidance for each model. When a door is unusually heavy, check that guidance instead of relying on habit.

Security: NRP pins and security studs

On an out-swinging door, the hinge knuckles and pins face the outside. With a standard pin, someone can tap the pin out and lift the door off without touching the lock. Two options stop that.

• Non-removable pin (NRP): a set screw or other locking feature keeps the pin in place while the door is closed. Specify NRP on every out-swinging door where the hinge side faces an unsecured area.
• Security studs: a stud on one leaf engages a hole in the other leaf when the door is closed, so the door stays in the frame even if the pins are removed. Some hinges include this feature.
• Hospital tips and button tips: these describe the pin ends. Hospital tips are sloped to reduce snag points, which matters in healthcare. They do not make a butt hinge ligature resistant, because the knuckles remain a ligature point; behavioral health rooms generally use ligature-resistant continuous hinges instead.

Other hinge options

• Material: steel or stainless steel for fire-rated doors; stainless or brass for wet or corrosive areas.
• Electric hinges: carry wires through the hinge to an electrified lock, exit device or door position switch. They replace one of the hinges, often the one nearest the device. The frame needs a raceway or box behind that hinge, so it must be on the frame order. See electric strike vs maglock.
• Swing clear hinges: an offset leaf swings the door fully out of the opening, so the full frame width is clear. They are common in healthcare where beds and wheelchairs need every inch, and can help meet ADA clear width without widening the frame.
• Finish: match the rest of the set. Steel hinges often use BHMA 652 to match 626 trim. See door hardware finishes.

When to move to a continuous hinge

If a door is very heavy, extremely high traffic or abused, a continuous hinge may serve better than butts. For most commercial openings, heavy weight ball bearing hinges sized correctly are the right answer. That choice is made type by type in the door hardware sets.