Ives 5BB1 4-1/2" x 4-1/2" Full Mortise Hinge - Five Knuckle - Ball Bearing - Standard Weight

The Ives 5BB1 is the five-knuckle, ball bearing, standard weight full mortise butt hinge for commercial and institutional interior and exterior doors. At 4-1/2" x 4-1/2", this is one of the most commonly specified sizes on commercial door schedules for hollow metal and wood doors in standard 1-3/4" applications. Ives hinges are an Allegion brand and are the default specified hinge on door hardware schedules that also include Schlage locks, LCN closers, Von Duprin exit devices, and other Allegion products, making finish matching across the full opening seamless.

Who Should Use the 5BB1 and Who Shouldn't

The 5BB1 standard weight is designed for doors under 150 lbs with medium-frequency usage under 400 cycles per day. Interior corridor doors, office doors, restroom doors, and light-use exterior doors in low-to-medium traffic buildings all fall within that envelope. The 5BB1 is also recommended for use with a door closer, which is standard practice on any commercial door.

If your door exceeds 150 lbs, uses a heavy-duty closer, or takes more than 400 cycles per day in a high-traffic application like a school corridor or healthcare facility, the correct upgrade is the Ives 5BB1HW heavy weight, which uses four ball bearing assemblies instead of two and is rated for those more demanding conditions.

Ball Bearings and Why They Matter

The 5BB1 standard weight hinge uses two ball bearing assemblies. Ball bearings reduce friction in the pivot point between the two hinge leaves. On a door that cycles dozens or hundreds of times per day, plain bearings wear down, create resistance, and eventually fail. Ball bearings distribute the load and roll rather than slide, extending the operating life of the hinge substantially and keeping the door swinging smoothly without adjustment or lubrication over time. The five-knuckle configuration distributes load more evenly along the hinge barrel compared to three-knuckle designs, reducing stress at the individual knuckle points.

Full Mortise Installation

The 5BB1 is a full mortise hinge, meaning both the door leaf and the frame leaf mortise into their respective surfaces. The door edge and the frame rabbet are routed to accept the hinge leaves flush with the surface. This is the standard installation method for hollow metal and commercial wood doors in virtually all commercial construction. Square corners are standard. The gauge for the 4-1/2" x 4-1/2" size is 0.134 inches.

Hardware Included

Each 5BB1 hinge ships with fasteners for both hollow metal and wood door installations. Hollow metal screws are 12-24 x 1/2" UFPHMS. Wood screws are 12 x 1-1/4" FPHWS. Both are included in the pack.

Certifications

Certified to ANSI/BHMA A156.1 for performance standards. Meets ANSI/BHMA A156.7 for template hinge dimensions, which means it fits the ANSI standard door prep without additional machining. UL Listed for 3-hour fire doors. UL Classified for windstorm-rated assemblies under classification R37965.

Materials and Finishes

Available in three base materials: 1040 steel, brass/bronze, and 304 series stainless steel. The 4-1/2" x 4-1/2" size carries the 0.134" gauge. The 5BB1 is available in over 20 finishes to match any door hardware schedule including USP Primed, US3 Polished Brass, US4 Satin Brass, US10 Satin Bronze, US10B Oil Rubbed Bronze, US15 Satin Nickel, US26 Polished Chrome, US26D Satin Chrome, US32 Polished Stainless, US32D Satin Stainless, and more. Optional configurations include non-removable pin (NRP), hospital tip, security stud, and electrified wire-through options.