Seal-tite 171-03 3 Inch Stub Collar No Crimp Duct Fitting

Product Description

The SEAL-TITE 171-03 is a 3-inch round stub collar designed for sheet metal duct systems in residential and commercial HVAC installations. This no-crimp collar is fabricated from galvanized metal at 30 gauge and stands 2 inches tall. It features a hemmed collar edge, a fully closed corner, an engineered throat and radii, a double-lapped construction, and a mechanically seamed corner and joint. These design elements support a secure, airtight connection at duct branch takeoffs and equipment transitions. Licensed HVAC technicians and sheet metal mechanics install this fitting as part of forced-air distribution systems.

The 171-03 is suited for round duct branch connections in forced-air heating and cooling systems where a stub collar transition is required. The no-crimp design eliminates the need to crimp the collar end before joining to adjacent ductwork, simplifying the connection process. Its galvanized steel construction resists corrosion in typical attic, basement, and crawl space installations. The bead feature adds rigidity to the collar opening and helps maintain roundness during handling and installation.

Key Features

• No-crimp design simplifies duct connections without additional forming steps
• 30-gauge galvanized metal construction for durability and corrosion resistance
• 2-inch collar height provides adequate engagement for secure duct attachment
• Hemmed collar edge reduces sharp edges and improves joint integrity
• Fully closed corner and mechanically seamed joint minimize air leakage
• Engineered throat and radii support consistent airflow characteristics

Compatibility

Designed as an OEM-style sheet metal fitting for 3-inch round duct systems in residential and light commercial forced-air HVAC applications meeting CCR/Title 24, IECC, HARDI, ACCA, AHREXPO, and ADI standards.

Installation Notes

Installation should be performed by a licensed HVAC technician or qualified sheet metal mechanic in accordance with applicable local mechanical codes and ACCA Manual D duct design guidelines. Power down the air handling unit and verify the system is de-energized before working on any duct section. Use appropriate sheet metal screws and UL 181-rated tape or mastic sealant to complete the joint per code requirements. Handle cut sheet metal edges with care to avoid injury.

Technical Specifications

• Size: 3 inches
• Height: 2 inches
• Type: Round
• Material: Galvanized Metal
• Material Thickness: 30 Gauge
• Features: Bead, Hemmed Collar, Fully Closed Corner, Engineered Throat and Radii, Double Lapped, Mechanically Seamed Corner and Joint
• Applicable Standards: CCR/Title 24, IECC, HARDI, ACCA, AHREXPO, ADI
• Series: 171

Standard Information

• Brand: SEAL-TITE
• Manufacturer Part Number: 171-03