Soss 418US26D Fire Rated Invisible Hinge Satin Chrome

Product Description

The SOSS 418US26D is a heavy-duty, fire-rated invisible hinge designed for commercial and residential doors requiring a clean, concealed appearance. Manufactured from alloy steel with a satin chrome finish, this hinge installs completely within the door edge and frame, leaving no exposed hardware when the door is closed. It is sized for 1.75-inch doors and measures 1.125 inches wide by 4.609 inches long, making it suitable for solid-core wood or metal doors found in fire-rated assemblies. Finish carpenters, millwork installers, and commercial door hardware specialists are the primary tradespeople who install this product.

This hinge is used in applications where surface-mounted hinges are undesirable, including high-end residential entries, office suites, hospitality interiors, and fire-rated corridor doors. Its fire-rated designation makes it appropriate for use in door assemblies required to meet fire door labeling standards. The heavy-duty alloy steel construction supports substantial door weight while maintaining the flush, invisible profile that architects and designers specify for premium installations.

Key Features

• Completely invisible when door is closed — no exposed barrel or leaves
• Fire-rated construction suitable for labeled fire door assemblies
• Heavy-duty alloy steel body for high-cycle durability
• Satin chrome finish (US26D) for corrosion resistance and low-glare appearance
• Sized for 1.75-inch door thickness
• Sold individually (each)

Compatibility

Designed as an OEM-style replacement or new-installation invisible hinge for 1.75-inch solid-core wood or metal doors in fire-rated and non-fire-rated assemblies requiring concealed hardware.

Installation Notes

Installation requires precise mortising into both the door edge and the door frame jamb using a router or dedicated SOSS hinge template. This work is typically performed by a finish carpenter, commercial door installer, or licensed door hardware specialist. Verify that the door assembly and frame are rated to accept fire-rated hardware before installation, and confirm compliance with applicable fire door standards such as NFPA 80. Do not install on doors exceeding the rated weight capacity for this hinge model.