3M 3520CW_48X45.7 Aluminum Foil Tape Hvac Duct

Product Description

The 3M 3520CW_48X45.7 is a silver aluminum foil tape designed for sealing, patching, and joining fibrous glass and sheet metal ductwork in HVAC systems. The tape measures 1.89 inches wide by 150 feet long with a 3.7 mil total thickness. It uses an acrylic adhesive system bonded to a malleable aluminum foil backing, which allows the tape to conform tightly to curved surfaces, corners, and irregular duct geometries. A kraft paper liner protects the adhesive until installation. The acrylic adhesive system performs reliably across a wide service temperature range, making it appropriate for both supply and return duct applications where heat and humidity cycling are routine.

This tape is suited for residential and light commercial HVAC installations where duct sealing integrity is required. It is applied directly to fibrous glass duct board, flex duct collars, and sheet metal fittings without special application tools. The hand-tearable foil backing speeds up field work, allowing technicians to cut and apply lengths on the fly. Typical uses include sealing longitudinal seams, patching small penetrations, and securing insulation jackets. The easy-release kraft liner allows for clean, controlled unwind without adhesive bridging.

Key Features

• Malleable aluminum foil backing conforms to curved surfaces, corners, and irregular duct geometries
• Acrylic adhesive rated from -40 to 250 degrees F for consistent bond through thermal cycling
• Hand-tearable — no knife or dispenser required for field cuts
• Easy-release kraft paper liner prevents premature adhesive contact during handling
• Meets UL 723 and manufactured under ISO 9001 quality standards
• 3.7 mil total thickness provides durable, puncture-resistant seal on duct seams

Compatibility

Designed for use on HVAC fibrous glass duct board and sheet metal duct systems. Suitable for both supply and return air duct sealing applications per the manufacturer's stated application guidance.

Installation Notes

Applied by licensed HVAC technicians or qualified installers as part of duct sealing work covered under mechanical codes such as the IMC and SMACNA standards. Power down the air handler before accessing interior duct runs. Clean and dry all surfaces before applying tape — oil, dust, or moisture will reduce adhesive contact and long-term bond strength. Do not stretch the foil during application, as this reduces the ability of the backing to conform to surface irregularities.

Technical Specifications

• Width: 1.89 inches (48 millimeters)
• Length: 150 feet (45.7 meters)
• Thickness: 3.7 mil
• Color: Silver
• Backing Material: Aluminum
• Adhesive Type: Acrylic
• Liner Material: Paper (Kraft)
• Temperature Rating: -40 to 250 degrees F
• Application: HVAC Fibrous and Sheet Metal Duct
• Certifications: UL 723, ISO 9001

Standard Information

• Brand: 3M
• Manufacturer Part Number: 3520CW_48X45.7