Metalcraft ATT12 Air Tite Take-off 12 Inch Flanged Steel

Product Description

The METALCRAFT ATT12 is a 12-inch round air tite take-off fitting designed for duct branch connections in forced-air HVAC systems. Fabricated from 28-gauge steel with a hot-dipped galvanized finish, it provides corrosion resistance suitable for both supply and return trunk-line applications. The flanged connection style allows for a secure, repeatable attachment to rectangular or round duct sections. This fitting is installed by licensed HVAC technicians and sheet metal mechanics during new construction or retrofit duct work.

The ATT12 is used in residential and light commercial forced-air distribution systems where a 12-inch round branch takeoff is required from a main trunk duct. The flanged collar seats firmly against the trunk wall, reducing air leakage at the connection point. Its round shape accommodates standard 12-inch flexible or rigid spiral duct. This fitting is a common component in supply plenum layouts and multi-branch distribution designs.

Key Features

• 12-inch round fitting size for compatibility with standard 12-inch duct
• 28-gauge steel construction for structural rigidity in duct systems
• Hot-dipped galvanized finish provides corrosion resistance
• Flanged connection type ensures a positive, low-leak seat against trunk duct
• Round shape fits standard flexible and rigid spiral duct collars
• Part of the ATT Series for consistent sizing and fitment across branch runs

Compatibility

Designed as an OEM-style sheet metal fitting for use with standard 12-inch round duct in residential and light commercial forced-air HVAC distribution systems.

Installation Notes

Installation should be performed by a qualified HVAC technician or licensed sheet metal mechanic. Power down the air handling unit and verify zero airflow before cutting into an existing trunk duct. Secure the flanged collar to the trunk with sheet metal screws and seal all edges with UL 181-rated mastic or approved foil tape per local mechanical code requirements. Do not overtighten fasteners on the 28-gauge steel body, as deformation can compromise the air seal.