National Mfg N830-425 3.5in Square Corner Hinge Black 15-pack

Product Description

The NATIONAL MFG/SPECTRUM BRANDS HHI N830-425 is a 3.5-inch square corner full mortise door hinge finished in black. Built from heavy-gauge cold-rolled steel, it delivers the structural integrity required for residential and light commercial door applications. The five-knuckle design distributes load evenly across the barrel, while the flush pin provides a clean, finished appearance once installed. Countersunk screw holes accept the included fasteners, keeping the installation tidy and reducing the need for additional hardware. The removable pin simplifies door hanging and removal during service work.

This hinge is suited for interior and exterior door installations where a square corner mortise profile is required. It is commonly specified for wood-framed doors in residential construction, remodel work, and commercial tenant improvement projects. The black finish coordinates with dark hardware sets. Each package contains 15 hinges, making it practical for contractors outfitting multiple doors on a single job. Carpenters, finish contractors, and general contractors are the primary installers.

Key Features

• Heavy-gauge cold-rolled steel construction for added strength and durability
• Five-knuckle, full mortise design for even load distribution
• Square corner profile for standard mortise door prep
• Flush pin delivers a clean, finished appearance
• Countersunk screw holes with fasteners included
• Removable pin for straightforward door installation and removal

Compatibility

Designed as an OEM-style replacement or new-installation hinge for standard full mortise square corner door preparations in residential and light commercial applications.

Installation Notes

Installation is performed by carpenters or finish contractors using a chisel and drill for mortise preparation. Ensure the door and frame mortises are cut to the correct depth before seating the hinge leaf to maintain a flush surface. All fasteners are included; pre-drilling pilot holes in hardwood door frames is recommended to prevent splitting. Verify local building codes for hinge quantity requirements per door height and weight.