Southwark Metal 84ST2_7IN Ductboard Collar 7 Inch Round

Product Description

The Southwark Metal 84ST2_7IN is a round sheet metal ductboard collar start fitting used to connect round duct runs to ductboard plenum or trunk systems. Fabricated from hot dip galvanized steel, it resists corrosion in both supply and return air applications. The 1-1/2 inch tab design allows the collar to be inserted and locked into ductboard material without additional fasteners at the board interface. At 7 inches in diameter, it fits standard round duct of that size and is installed by sheet metal and HVAC technicians during new construction or system retrofit work.

This collar start is suited for residential and light commercial HVAC duct systems where ductboard is used as the primary plenum or branch duct material. It serves as the transition point where a round metal duct originates from a ductboard surface. The tab design secures the fitting flush against the ductboard face, creating a reliable air seal when properly installed with approved duct adhesive or mastic per SMACNA and ACCA guidelines.

Key Features

• Hot dip galvanized steel construction for corrosion resistance in HVAC air distribution environments
• 1-1/2 inch tab for positive engagement with ductboard material
• 7 inch diameter fits standard round duct of the same size
• Round profile for connection to flexible or rigid round duct runs
• Meets ACCA and SMACNA applicable standards

Compatibility

Designed as an OEM-style replacement and new-installation fitting for residential and light commercial ductboard-based HVAC air distribution systems using 7 inch round duct connections.

Installation Notes

Installation is performed by licensed HVAC or sheet metal technicians. Shut down the air handling unit and isolate the system before cutting into ductboard or making duct connections. The tab should be inserted through a field-cut hole in the ductboard and folded flat against the interior surface; seal all joints with UL 181-listed mastic or tape per SMACNA installation standards. Follow local mechanical codes and ACCA Manual D requirements for duct system design and fitting placement.

Technical Specifications

• Diameter: 7 inches
• Tab Length: 1-1/2 inches
• Profile: Round
• Material: Hot Dip Galvanized Steel
• Applicable Standards: ACCA, SMACNA

Standard Information

• Brand: Southwark Metal
• Manufacturer Part Number: 84ST2_7IN