Full mortise, door and frame
ANSI/BHMA A156.1 · A156.18 · NFPA 80
Maryland, DC & Northern Virginia
A butt hinge is two flat leaves joined by a pin that runs through rolled knuckles. One leaf is cut into the door edge and the other into the frame, so the hinge sits flush when the door closes. Most commercial doors hang on three or four of them.
They hold the door’s weight, guide its swing, and keep the latch aligned with the strike. When butt hinges are sized and graded correctly, the door closes smoothly, latches every time, and stays secure for years.
Butt hinges cost less per opening than continuous hinges or pivots, stretching budgets across many doors.
One worn hinge swaps out in minutes, using existing frame preps and keeping doors in service.
Properly sized steel ball bearing hinges satisfy NFPA 80, with electric and security versions available too.
King Locksmith And Doors Inc. is a commercial locksmith and door company serving Maryland, Washington DC, and Northern Virginia. We work with small businesses, government agencies, healthcare facilities, hotels, and large enterprises. Our technicians install, repair, and replace butt hinges on hollow metal and wood doors. We check door weight, daily traffic, and fire ratings before we recommend a single hinge. That way, every opening we touch swings freely, latches reliably, and passes inspection.
The right butt hinge depends on your door, not just the frame prep. Use these five checks to match grade, size, bearing type, material, and special features to how each opening gets used every day.
ANSI/BHMA A156.1 rates butt hinges by cycle testing. Grade 1 hinges pass 2.5 million open-and-close cycles. Grade 2 hinges pass 1.5 million, and Grade 3 pass 350,000. Higher grades use thicker leaves.
Choose Grade 1 for main entrances, stairwells, restrooms, and any door with a closer. Grade 2 suits offices and moderate interior traffic. Grade 3 is best kept for closets and low-use rooms. Upgrading the grade costs little and often adds years of service.
Hinge height follows door thickness and width. A standard 1¾-inch commercial door up to 36 inches wide usually takes a 4½-inch hinge. Wider or heavier doors step up to 5 inches. Hinge width must clear trim so the door can swing fully.
Count one hinge for every 30 inches of door height. A 7-foot door needs three, and an 8-foot door needs four. Doors over 36 inches wide, or with heavy traffic, need heavy-weight hinges.
Bearings sit between the knuckles and carry the door’s weight as it turns. Ball bearing hinges use hardened steel balls, so they swing with less friction and wear slowly. Plain bearing hinges have no balls and wear faster under load.
Use ball bearing hinges on every door with a closer, on heavy doors, and on most fire-rated doors. Plain bearing hinges are fine for light interior doors that see little traffic and have no closer.
Steel hinges are strong and cost-effective for most dry interior doors. Stainless steel resists rust, so it fits exterior doors, restrooms, kitchens, and hospitals that clean with harsh chemicals every day. Brass and bronze look upscale but need more care outdoors.
Fire-rated doors need steel or stainless steel hinges. Common finishes include satin chrome (US26D), satin stainless (US32D), and oil-rubbed bronze (US10B). Matching the finish to your locks and closers keeps every opening looking consistent.
Out-swinging exterior doors expose hinge pins to the outside. Non-removable pin (NRP) hinges stop anyone from tapping out the pin and lifting the door off. Electric hinges carry low-voltage wires through the hinge to power access control and electrified locks.
Hospital tip hinges have sloped ends that reduce ligature risk and are easier to clean. Swing clear hinges move the door fully out of the opening, adding usable width for wheelchairs, carts, and beds.
Continuous hinges run the full height of the door, while butt hinges mount at three or four points. Here is where butt hinges come out ahead for many commercial doors.
Consideration
Butt Hinges
Continuous Hinges
Lowest hardware cost per door opening
Higher price for hinge and labor
Replace one worn hinge at a time
Whole full-length hinge must be replaced
Fits standard hinge preps already in place
Retrofit may require door trimming or reinforcement
Steel ball bearing models follow NFPA 80 directly
Must be tested and labeled separately
Small, discreet knuckles suit traditional interiors
Full-length leaf stays visible along edge
Hinge problems often start small, then spread to the lock, closer, and frame. They are also a common fire door inspection finding. Watch for these warning signs on your doors.
We remove failing butt hinges and install matched replacements that fit your existing door and frame preps.
We re-hang dropped doors, tighten or reinforce hinge screws, and restore an even gap around the frame.
We swap plain bearing or low-grade hinges for Grade 1 ball bearing models on your busiest openings.
We correct hinge count, type, and fasteners on fire doors so they meet NFPA 80 inspection requirements.
We install power transfer hinges that route wiring safely to electrified locks, exit devices, and monitoring switches.
We fit non-removable pin and security stud hinges on out-swinging doors to stop hinge pin removal attacks.
Book a site visit. We will check every hinge, recommend the right grade and size, and send a clear quote.
