Sheet Metal Products Inc 421-161616 Duct Transition

Product Description

The SHEET METAL PRODUCTS INC 421-161616 is a square-to-round duct transition designed to connect a 16 x 16 inch square duct section to a 16 inch round duct section. This fitting is a standard component in low-pressure supply and return air distribution systems. HVAC technicians and sheet metal installers use this transition when a trunk line or plenum with a square or rectangular opening needs to feed into a round branch duct or flexible duct run. The part is sold as a single unit and is fabricated for direct field installation.

This transition is suited for residential and light commercial forced-air systems where square-to-round connections are required at air handlers, furnaces, or inline duct junctions. It is appropriate for installations where a 16 x 16 inch square collar mates to a 16 inch round duct, flex duct connector, or round takeoff fitting. No listed compatible model numbers or system families were provided in the product data.

Key Features

• Square-to-round configuration allows connection between square and round duct sections
• 16 x 16 inch square end matches standard trunk and plenum collar sizes
• 16 inch round end accepts standard round duct and flex duct connections
• Sold as a single unit for individual fitting replacement or new installation

Compatibility

Designed as an OEM-style sheet metal fitting for residential and light commercial forced-air duct systems requiring a 16 x 16 inch square-to-16 inch round transition.

Installation Notes

Installation is typically performed by a licensed HVAC technician or qualified sheet metal mechanic. Power down the air handling unit and verify the system is de-energized before cutting into or modifying ductwork. Secure the fitting using sheet metal screws and seal all joints with UL 181-rated foil tape or mastic sealant per local mechanical code requirements. Do not compress or restrict the round end opening during installation.