Southwark Metal 73C1738211416 Rectangular to Round Transition 17 3/8 Inches X 21 1/4 Inches X 16 Inches

Product Description

The Southwark Metal 73C1738211416 is a rectangular to round transition fitting designed for HVAC duct systems where airflow must shift from a rectangular duct opening to a round collar connection. This type of fitting is a standard component in forced-air heating, ventilation, and air conditioning installations. HVAC technicians and sheet metal contractors use rectangular to round transitions to connect trunk lines, air handlers, and plenums to round branch ducts or flexible ductwork. The 73C1738211416 has a rectangular inlet measuring 17 3/8 inches by 21 1/4 inches and transitions to a 16-inch diameter round collar. The overall height of the fitting is 12 inches, giving the transition a gradual, controlled taper that promotes smooth airflow and reduces turbulence inside the duct system. The collar height on fittings of 16-inch diameter and above is approximately 3 inches, which provides enough engagement for secure connection to round duct or flexible duct connectors. This fitting is fabricated from hot dipped galvanized steel meeting ASTM A653 CS Type B standards. The galvanized coating protects against rust and corrosion, making it suitable for both residential and light commercial duct installations. The steel is formed at 28 gauge, which is a common gauge specification for HVAC supply and return ductwork of this size. At approximately 4 pounds, the fitting is manageable for a single installer. It ships as an individual unit and is made in the USA. The 73C series from Southwark Metal covers a wide range of rectangular to round transition sizes, making it a go-to product line for custom and standard duct fabrication projects.

• Rectangular inlet: 17 3/8 inches x 21 1/4 inches transitioning to a 16-inch round collar for versatile duct connections
• Fabricated from 28-gauge hot dipped galvanized steel per ASTM A653 CS Type B for corrosion resistance and durability
• Made in the USA as part of the Southwark Metal 73C product family, available across a broad range of sizes

Product Highlights

The Southwark Metal 73C1738211416 rectangular to round transition is a galvanized steel duct fitting built for reliable HVAC duct connections in residential and commercial applications. Its 28-gauge construction and ASTM A653-compliant coating deliver long-term performance in forced-air systems.

Product Information

Standard Information

• Brand: SOUTHWARK METAL
• Manufacturer Part Number: 73C1738211416

Technical Specifications

• Rectangular Duct Size: 17 3/8 inches x 21 1/4 inches
• Round Collar Diameter: 16 inches
• Height: 12 inches
• Gauge: 28 GA
• Material: Galvanized Steel
• Galvanized Standard: ASTM A653 CS Type B
• Weight: 4.02 pounds
• Country of Origin: USA
• Unit of Measure: EA
• Prop 65: Yes