Southwark Metal 121SC8 Ductboard Snaplock Collar 8 in

Product Description

The SOUTHWARK METAL 121SC8 is an 8-inch ductboard snaplock collar designed for connecting round duct to ductboard plenum and air distribution systems. This sheet metal fitting creates a secure, snap-fit mechanical connection at the ductboard surface, maintaining airflow integrity at the transition point. It is a standard component in residential and light commercial HVAC duct fabrication and is installed by licensed HVAC technicians and sheet metal contractors working with fiberglass ductboard systems.

The 121SC8 is used in forced-air HVAC applications where rigid fiberglass ductboard serves as the primary distribution plenum or branch duct material. The collar fits into a cutout made in the ductboard surface and locks into place, providing a stable mechanical seat for round flex duct or round rigid duct connections. It is a common component in new construction and replacement ductwork projects requiring an 8-inch branch takeoff.

Key Features

• 8-inch diameter snap-lock design for fast, tool-minimized installation into ductboard
• Sheet metal construction provides a rigid, durable connection point at the ductboard face
• Snap-lock retention mechanism seats securely without fasteners for a reliable fit
• Compatible with standard 8-inch round duct connections in forced-air distribution systems
• Suitable for residential and light commercial HVAC ductboard plenum applications

Compatibility

Designed as an OEM-style replacement and new-installation fitting for use with fiberglass ductboard systems requiring an 8-inch round duct collar connection.

Installation Notes

Installation is performed by qualified HVAC technicians or sheet metal contractors. Power down the air handling unit and close the system before cutting into an existing ductboard plenum. Score and cut the ductboard opening to the correct diameter before inserting the collar, and verify the snap-lock tabs are fully engaged around the perimeter. Ductboard installations should comply with SMACNA and applicable local mechanical code requirements.

Technical Specifications

• Diameter: 8 inches
• Connection Type: Snaplock
• Application: Ductboard Systems

Standard Information

• Brand: SOUTHWARK METAL
• Manufacturer Part Number: 121SC8