National Guard Products 120SSS Silicone Perimeter Weatherstrip – Stainless Steel Head-and-Jamb Set

National Guard Products (NGP) model 120SSS is a stainless steel silicone perimeter weatherstrip supplied as a complete head-and-jamb set (one head piece plus two jamb pieces) in a Brushed #4 Stainless Steel finish (US32D / 630) with a black closed-cell silicone insert. Screw-applied directly to the frame stop, the 120SSS is available in five standard opening sizes — 3'0 x 7'0, 4'0 x 7'0, 6'0 x 7'0, 6'0 x 8'0, and 8'0 x 8'0 — and is made to order with a typical lead time of 10–15 business days. Its UL-certified fire, positive-pressure, and smoke-and-draft-control ratings make it one of the most specification-ready perimeter gasketing systems available for hollow metal and wood fire-rated door assemblies in commercial, institutional, and high-security environments.

Key Features of the NGP 120SSS Stainless Steel Silicone Perimeter Seal

• Stainless Steel Type 304 Housing: Corrosion-resistant Type 304 stainless steel retainer provides long-term durability in demanding or high-humidity environments.
• Closed-Cell Silicone Sponge Insert: The synthetic rubber polymer (closed-cell sponge) silicone gasket delivers excellent flexibility and memory, conforming tightly to door frames and returning to its original shape after each door cycle.
• Extreme Temperature Performance: Rated from -81°F to 300°F, this silicone gasket remains flexible at extreme temperatures, making it suitable for cold-storage facilities, high-heat industrial applications, and fire-rated assemblies alike.
• Flame-Resistant and Moisture-Resistant: The closed-cell silicone construction resists flame spread and prevents moisture infiltration, protecting door openings against weather and environmental exposure.
• Superior Environmental Resistance: Offers excellent resistance to ozone, UV radiation, and aging, maintaining a reliable seal over the life of the door assembly without cracking or degrading.
• FM200 and Halon Compatible: Specifically recommended for areas utilizing FM200 or Halon fire suppression systems, where gasket material compatibility with suppression agents is critical to system integrity.
• UL-Certified Fire Door Rating: Certified by UL to CAN/ULC-S104 and ANSI/UL10B; complies with NFPA 80 and NFPA 252 for hollow metal fire doors rated up to 3 hours and wood fire doors rated up to 90 minutes.
• UL-Certified Positive Pressure: Certified by UL to ANSI/UL10C; complies with IBC, NFPA 80, and NFPA 252 for positive-pressure hollow metal fire doors up to 3 hours and wood fire doors up to 90 minutes.
• Smoke and Draft Control Gasketing – UL Category 'H': Certified by UL to ANSI/UL10C and ANSI/UL1784 Category 'H'; complies with IBC and NFPA 105 for use on 'S'-labeled positive-pressure hollow metal fire doors up to 3 hours and wood fire doors up to 90 minutes.
• ANSI/BHMA A156.22 Certified: Certified gasketing complies with the American National Standard for Door Gasketing and Edge Sealing Systems and is listed in the BHMA Certified Products Directory. Also certified to ANSI/BHMA A156.22 performance tests for heat and cold.
• Air Infiltration Control: Recommended for minimum air leakage applications, delivering a tight perimeter seal that supports energy efficiency and indoor climate management.
• Slotted Screw Holes for Field Adjustment: Screw holes are slotted to allow precise on-site alignment adjustment after installation, simplifying fitting to real-world frame conditions.
• Stainless Steel Fasteners Furnished: #6 x 3/4" stainless steel sheet metal screws (SMS) are included, ensuring corrosion-consistent fastening that matches the housing material.
• Head-and-Jamb Set in Five Opening Sizes: Supplied as a complete three-piece perimeter set sized for openings of 3'0 x 7'0, 4'0 x 7'0, 6'0 x 7'0, 6'0 x 8'0, or 8'0 x 8'0, reducing field cutting and material waste.

Technical Details

Pro Tip: Because screw holes are slotted, installers can shift the retainer slightly after initial placement to achieve a consistent compression fit across the full door height and width before final tightening. Stainless steel SMS fasteners are furnished with each set, so no separate hardware sourcing is required for a standard frame-stop application.