Mm Manufacturing 641R6-10X8X8 Insulated Box Snap Rail Flange

Product Description

The MM Manufacturing 641R6-10X8X8 is an insulated sheet metal box fitting with a snap rail flange, designed for use in residential and light commercial HVAC duct systems. The snap rail flange allows for fast, tool-minimal connection to duct runs, reducing installation time at rough-in. Measuring 10 x 8 x 8 inches nominal with a packaged footprint of 12 inches in length, 10 inches in width, and 6.75 inches in height, this fitting ships compact and installs into standard rectangular duct configurations. At 2.1 pounds, it is lightweight enough for single-technician handling in tight plenum or chase spaces.

This insulated box fitting is suited for supply-side duct applications in forced-air systems where thermal efficiency and condensation resistance are priorities. The integral insulation limits heat transfer through the fitting body, maintaining supply air temperature between the air handler and the diffuser. It is appropriate for new construction rough-in and retrofit duct modification work performed by licensed HVAC technicians and sheet metal installers.

Key Features

• Snap rail flange design allows fast connection to duct sections without additional flanging tools
• Integral insulation reduces heat gain and condensation risk along the supply duct path
• Nominal 10 x 8 x 8 inch size fits standard rectangular duct opening configurations
• Lightweight at 2.1 pounds for easy single-tech handling in confined spaces
• Compact packaged dimensions simplify transport and jobsite staging

Compatibility

Designed as an OEM-style replacement and new-installation fitting for standard residential and light commercial rectangular supply duct systems using snap rail duct construction.

Installation Notes

Installation should be performed by a qualified HVAC technician or licensed sheet metal installer in accordance with local mechanical codes and SMACNA duct construction standards. Power down the air handling unit and close the system disconnect before working inside any plenum or duct enclosure. Ensure the snap rail connection is fully seated and sealed with code-approved mastic or metal-backed tape to prevent air leakage at the joint. Do not compress or puncture the insulation facing during fitting, as damage to the insulation layer reduces its thermal and vapor-barrier performance.

Technical Specifications

• Nominal Size: 10 x 8 x 8 inches
• Packaged Length: 12 inches
• Packaged Width: 10 inches
• Packaged Height: 6.75 inches
• Weight: 2.1 pounds
• Flange Type: Snap Rail
• Insulation: Included

Standard Information

• Brand: MM Manufacturing
• Manufacturer Part Number: 641R6-10X8X8