BB31 4-1/2 x 4-1/2 BALL BEARING .134 HINGE

Cal-Royal BB31 Ball Bearing Hinge – 4-1/2" x 4-1/2", .134 Gauge

Reliable, Smooth Operation for Medium-Duty Commercial Doors

The Cal-Royal BB31 is a full mortise, five-knuckle ball bearing hinge designed for medium-frequency doors in commercial and institutional settings. Built with precision and durability in mind, it ensures smooth door operation and long-lasting performance.

🔧 Key Features:

• Full mortise hinge with five knuckles for enhanced stability and alignment
• Two permanently lubricated ball bearings reduce friction and wear
• Standard weight design with .134" gauge thickness for medium-duty applications
• Constructed from high-quality 1040 steel or 304 stainless steel for strength and corrosion resistance
• Size: 4-1/2" x 4-1/2" – fits most commercial wood or hollow metal doors
• Meets ANSI/BHMA A156.1 standards for commercial-grade hinges
• Available with Non-Removable Pin (NRP) option for added security on outswing doors
• Supplied with fasteners for both wood and metal door frames
• Compatible with door closers and recommended for medium-frequency usage
• Offered in multiple architectural finishes including Satin Chrome (US26D), Satin Stainless Steel (US32D), Satin Brass (US4), and Flat Black (US1/622)

✅ Why Choose the Cal-Royal BB31?

• Ideal for offices, schools, healthcare facilities, and light commercial environments
• Provides smooth, quiet door movement with reduced maintenance needs
• Enhances door security and performance with durable ball bearing design
• Backed by Cal-Royal’s commitment to quality and reliability

Upgrade your door hardware with the Cal-Royal BB31 – engineered for smooth performance and built to last.