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3M

3M Aluminum Foil Tape 3340, 2.5" x 50 yd, 4.0 mil, Silver, HVAC, Sealing and Patching Hot and Cold Air Ducts, Fiberglass Duct Board, Insulation, Metal Repair

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Availability: In Stock.
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Arrives Thursday, Jun 11
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Color: Silver


Pattern Name: 2.5" x 50 YD


Features

  • VAPOR SEAL TAPE: 2.0 mil aluminum foil backing (4.0 mil total thickness) with a strong, pressure sensitive acrylic adhesive is ideal as a vapor seal tape for duct closure.
  • HOT AND COLD TEMPERATURES: Combination of a foil backing and acrylic adhesive gives this tape a superb operational temperature range of -40F-300F (-40C-149C).
  • LONG LASTING: The foil backing serves as an excellent barrier against moisture, dust and many chemicals - making it strong, durable and long-lasting.
  • APPLICATIONS: Heating Ventilation Air Conditioning (HVAC), duct closure, vapor seal on reinforced fiberglass duct board, rigid fiber glass duct board, flexible air ducts and air connectors.
  • Listed for both UL181A-P and UL181B-FX

Description

When sealing ducts and other surfaces for heating, ventilation and air conditioning systems (HVAC), it's essential to have a strong, long-lasting foil tape that can stand up well to hot and cold temperatures. The 3M Foil Tape 3340 has the combination of 2.0 mil aluminum foil backing and strong, pressure sensitive acrylic adhesive that gives our tape a superb operational temperature range of -40°F (-40°C) to 300°F (149°C) making it ideal for sealing rigid fiberglass duct boards and flexible air duct systems. The foil backing also serves as an excellent barrier against moisture, dust and many chemicals — making it strong, durable and long-lasting. The very low moisture vapor transmission rate makes the tape a good sealant and the acrylic adhesive supplies superior temperature and UV resistance to give you a strong, lasting and reliable bond. It also has an easy releasing poly coated kraft paper liner to protect the adhesive and keep the tape ready for use. 3340 tape meets requirements for UL 181 A-P and UL 181 B-FX Listings as a measure of reliability and quality standards. 3M Foil Tape 3340 is used in a variety of applications including heating ventilation air conditioning (HVAC), duct closure, vapor seal on reinforced fiberglass duct board, rigid fiber glass duct board, and flexible air ducts and air connectors across a number of industries, including: transportation, specialty vehicle, metalworking, construction, automotive, military and government, general industrial, MRO, electronics and aerospace.

Brand: 3M


Color: Silver


Material: Acrylic


Number of Items: 1


Recommended Uses For Product: Sealing


Product Dimensions ‏ : ‎ 5.5 x 0.5 x 0.5 inches; 0.8 ounces


Item model number ‏ : ‎ 40132


Date First Available ‏ : ‎ April 5, 2021


Manufacturer ‏ : ‎ 3M


Best Sellers Rank: #2,803 in Industrial & Scientific (See Top 100 in Industrial & Scientific) #29 in Duct Tape


#29 in Duct Tape:


Customer Reviews: 4.7 4.7 out of 5 stars (1,952)


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Thursday, Jun 11

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews

    • Don't skimp! This is worth the money!
Color: Silver Pattern Name: 2.5" x 50 YD
This is the best tape we've ever used! Very sticky and stays on!
Reviewed in the United States on November 18, 2025 by Tamelak
    • Foil tape
Color: Silver Pattern Name: 2.5" x 50 YD
Works and sticks good sealing duct frame for filters. USN came out with duct tape, submarines would use it to stick problem people to ceilings (no joke)
Reviewed in the United States on December 27, 2025 by J R
    • The high quality aluminum “duct” tape
Color: Silver Pattern Name: Tape
This is the good one, this stuff is tough too. I always like to have some on hand for projects around the house. You’d be surprised how useful this tape can be once you have some on hand. My dad always used this at work (HVAC) so I’ve learned over the years how to properly use this tape to make my A/C more efficient. This is great for taping up cracks around your furnace or condenser coil. You can also use it to tape the chill line near the outside unit if your lines have areas that are exposed, or if there are places that are beginning to be exposed. You can buy cheaper brands, but there’s some things you shouldn’t buy off brand, and this one of them. Buy the legit 3M tape, it’s worth it. It’ll save you money in the long run as you won’t constantly be having to patch up previous applications. I’m not a certified HVAC tech, but after riding with my dad from elementary school until I graduated, I do know to highly recommend this specific tape. This can also be used on small windows, such as the small window panes on some front/back doors, and for lots of other applications. If you’re a homeowner, I truly believe a roll of this tape should be in your home tool box. ... show more
Reviewed in the United States on August 23, 2023 by Phoenix Lain
    • Great tape! Unfortunately received dirty and not as described from seller!
Color: Silver Pattern Name: 2.5" x 50 YD
Great tape! Unfortunately received dirty and not as described from seller! I use this tape all the time…best tape for my needs! This item was Described as "Looks and functions as if it were new. Item will come in original packaging.” sold by Amazon.com Services, Inc. Unfortunately it was not in it’s original packaging…and a plastic bag over it. It was also dirty. I will keep it and use it anyway. Wish the description was more accurate…I paid too much for the condition I received! ... show more
Reviewed in the United States on May 13, 2025 by Lisa W
    • 3M MAKES GOOD STUFF
Color: Silver Pattern Name: Tape
Purchased for A/C ducts in the attic, the insulation was torn and falling off. This seems to be top quality tape, very sticky, cuts with heavy duty scissors or shears, a little pricy, but you get what you pay for! All the other 3M products I purchased have been of top quality! I most likely will need a second roll of tape to really secure the duck work, it even looks good and professional, words often not used when I do a job! ... show more
Reviewed in the United States on February 6, 2025 by craig
    • Every Homeowner should Own This
Color: Silver Pattern Name: 2.5" x 50 YD
Used this to make repairs my HVAC guy missed. Super easy to use and seals around ventilation system. Every homeowner should have a roll of this.
Reviewed in the United States on December 22, 2025 by DJ
    • Best HVAC Tape I Ever Used & Will Always Use
Color: Silver Pattern Name: 2.5" x 50 YD
I have been doing heating and air conditioning with going to school over 30 years ago. Yes, you will find much aluminum tape that is less expensive on Amazon for sure. I have always used this with it being made by 3M knowing how good it is and would say out of all different aluminum tapes. I’ve used this is 10 times better than any other tape I ever used. Surprises me it’s not much more expensive with how unbelievable it really is and if you purchase it versus cheaper ones, you know by the odor of the adhesive that is on it. Other stuff I’ve used did not only stick the greatest. Yes it’s stuck on any ductwork. I put it on this made by 3M. Wow. Even if you do not do HVAC for a living and need aluminum tape, this is beyond your best choice believe me. ... show more
Reviewed in the United States on July 21, 2025 by Jerry
    • It does what it's supposed to do; BUY IT!
Color: Silver Pattern Name: 2.5" x 50 YD
VERY strong and reliable (3M). I trust this brand!
Reviewed in the United States on July 28, 2025 by JMB Communications

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