SOSS 418SS Stainless Steel Invisible Hinge with 90/180-Minute Fire Rating

SOSS 418SS Stainless Steel Invisible Hinge with 90/180-Minute Fire Rating

The SOSS 418SS Invisible Hinge is engineered for wood or metal doors that are 1-3/4" thick, delivering a flush fit and compact concealed profile for full sized entry applications. Constructed entirely of 316 stainless steel, this heavy-duty hinge opens a full 180° as a single action hinge and resists corrosion in exterior, wood, and metal installations. Underwriters Laboratories has labeled the 418SS for use on hollow metal, sheet metal, tin clad, and steel composite swinging fire doors and frames rated up to and including 3 hours, wood core doors and frames rated up to 20 minutes, and wood/plastic composite doors and frames built with Georgia Pacific FS 1 or FS 2 banding rated up to and including 90 minutes. Wood and machine screws are included for straightforward installation.

Key Features

• Material Thickness Compatibility: Designed for wood or metal doors and frames with a minimum material thickness of 1-3/4" for proper flush installation.
• Heavy-Duty Corrosion Resistance: Made of complete 316 stainless steel construction, ideal for exterior applications and environments requiring superior corrosion resistance.
• Full 180° Single Action Operation: Provides smooth, reliable swing operation across a full range of motion for full sized entry doors.
• Invisible Concealed Design: Flush fit and compact size deliver a clean appearance while maintaining durability in high-use commercial settings.
• Fire-Rated Performance: UL labeled for use on hollow metal, sheet metal, tin clad, and steel composite fire doors rated up to and including 3 hours, wood core doors rated up to 20 minutes, and wood/plastic composite doors with Georgia Pacific FS 1 or FS 2 banding rated up to and including 90 minutes.
• Included Hardware: Wood and machine screws are included, and counter bored screw holes are not required for this model.
• Application Guidance: Use at least one fire-rated hinge for every 20" of door height or portion thereof, or one hinge for every 60 lbs. or fraction thereof, whichever demands more hinges.
• Rounded Corner Design: Part of the 418 Series, featuring a rounded corner profile and a product size of 4-39/64" for compatible door preparation.

Certifications & Compliance

• UL Labeled for Fire Door Applications
• Fire Rating: 90 / 180 Minutes

Technical Specifications

• Subcategory: Hinges and Pivots
• Product Group: Door Hinges and Pivots
• Product Subgroup: Concealed Hinges
• Commercial/Residential: Commercial
• Duty Level: Heavy Duty
• Electronic: No
• Corner Type: Rounded
• Series: 418 Series
• Product Size: 4-39/64"
• Product Category: Door Hinges and Pivots
• Department: Door Hardware
• Application: Exterior, Full Sized Entry, Metal, Wood
• Min. Material Thickness: 1-3/4″
• Fire Rating: 90 / 180 Minutes
• Power Transfer: No
• Closer: No
• Counter Bored Screw Holes: No
• Screws Included: Wood and Machine
• Packaging: 1 / Box = 1 Each
• Packages Per Container: 1 Each
• Price Per: Each

Typical Applications

• Commercial Office Buildings
• Educational Facilities
• Healthcare Institutions
• Retail Establishments
• Industrial and Warehouse Facilities
• Multi-Tenant Residential Properties
• Government and Municipal Buildings

Why SOSS 418 Series?

SOSS 418 Series hinges deliver professional-grade reliability with complete 316 stainless steel construction and UL-labeled fire ratings up to 3 hours on qualifying door and frame assemblies. Engineered for demanding commercial entry applications where flush appearance, smooth single action operation, and long-term corrosion resistance are essential.