Mm Manufacturing 400-5X4 Tapered Reducer 5x4 Inch Duct

Product Description

The MM MANUFACTURING 400-5X4 is a tapered reducer fitting designed to transition between two different duct diameters in forced-air HVAC systems. This fitting steps down from a 5-inch connection to a 4-inch connection using a gradual taper, which helps maintain airflow velocity and minimize turbulence at the transition point. Weighing 0.35 pounds and measuring 7 inches in length, it is a lightweight, easy-to-handle component suited for both new installations and service replacements. HVAC technicians and sheet metal installers are the primary trade professionals who work with this type of fitting.

This tapered reducer is used wherever a duct run requires a diameter change, such as branching off a trunk line, connecting to a smaller collar on a diffuser, or adapting between equipment and ductwork of differing sizes. It is appropriate for residential and light commercial forced-air applications. The 400 series from MM MANUFACTURING spans 42 size combinations ranging from 4 inches x 3 inches up to 24 inches x 22 inches, making it part of a broad family of compatible reducers for varied system layouts.

Key Features

• Tapered profile transitions from 5 inches to 4 inches to support smooth airflow through the duct system
• 7-inch overall length provides gradual reduction geometry to limit pressure drop at the transition
• Lightweight at 0.35 pounds for easy single-technician handling and positioning
• Part of the 400 series, which covers 42 size combinations for flexible system design

Compatibility

Designed as an OEM-style replacement or new-installation fitting for residential and light commercial forced-air duct systems requiring a 5-inch to 4-inch diameter transition.

Installation Notes

Installation is typically performed by a licensed HVAC technician or sheet metal installer. The air handling unit or furnace should be powered down before modifying any ductwork. Secure the fitting with sheet metal screws and seal all joints with UL-listed foil tape or mastic sealant in accordance with local mechanical codes and SMACNA guidelines. Do not over-compress the fitting during installation, as deformation can restrict airflow.

Technical Specifications

• Inlet Diameter: 5 inches
• Outlet Diameter: 4 inches
• Length: 7 inches
• Width: 5 inches
• Weight: 0.35 pounds

Standard Information

• Brand: MM MANUFACTURING
• Manufacturer Part Number: 400-5X4