3M™ Scotch-Weld™ Structural Adhesive Film AF 31

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Designed for 350°F (175°C) cure

Good flexibility and shear strength at service temperatures from -67°F to 500°F (-55°C to 260°C)

Easy application in a film form which can be pressure, heat or solvent tacked in position

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  • Designed for 350°F (175°C) cure
  • Good flexibility and shear strength at service temperatures from -67°F to 500°F (-55°C to 260°C)
  • Easy application in a film form which can be pressure, heat or solvent tacked in position
  • Excellent retention of strength after aging in many environments
  • Yellow in color
  • Suitable for metal-to-metal bonding

Our 3M™ Scotch-Weld™ Structural Adhesive Film AF 31 is a yellow colored adhesive film that provides long-term durability and meets specific challenges for metal-to-metal bonded structures where high temperature performance is desired.

Ready to Fly
3M™ Scotch-Weld™ Structural Adhesive Film AF 31 provides excellent performance with easy-to-use shop handling properties. With good peel strength, AF 31 provides reliable, long-term durability and meets the specific challenges of metal-to-metal bonded structures.

Overlap Shear on Aluminum

Cure Cycle Overlap Shear (psi)
Test Temperature
Temp. Time Pressure Rise Rate
(°F) (°C) (min.) (psi) (°F/min) -67°F
350 177 60 150 200 2700 3700 2850 2500 2390 1700 1150 1100 800 250
350 177 10 150 200 2850 4200   2430 1975          
350 177 5 150 200 2260 4200   2260 1610          
350 177 60 45 200 2675 3740     2050          
350 177 60 45 9 2800 3700     2100     1300    
350 177 120 100 10         2647   2165   1790  
250 121 120 75 10   4285     1225          
250 121 24 hrs. 75 10   4375     2090          
260 127 120 75 10   4150     1510          
260 127 8 hrs. 75 10   4360     2000          
325 163 60 20 200 2720 3360 1830 1370 840          
350 177 60 20 200 2820 3280 2020 1720 1530          

The following 3M primer is compatible with AF 31:
3M™ Scotch-Weld™ Structural Adhesives Primer EC-2174

AF 31 supplies peel strength through a spectrum of environmental conditions and are easy to work with. Once cured it provides high bond strength from -67°F to 500°F (-55°C to 260°C) for use in challenging designs in multiple environments.

What is Structural Adhesive Film?
The fewer rivets you have in your aircraft the better. Structural adhesive films enable the designer to get more innovative with their parts, and reduce the overall number of rivets required on your structure. This thermosetting modified epoxy in film form can be used for bonding a wide variety of substrates, including metal, honeycomb and composite. Structural Adhesive Films come in a variety of weights and thicknesses, minimizing the weight while maintaining the structural integrity.

Multi-colored honeycomb panels for aircraft bonded with structural adhesive films.
3M adhesive films are designed to deliver superior mechanical performance in challenging conditions
The films are available in supported versions, which are typically used for monolithic bonding or honeycomb sandwich. They are also available in unsupported form for reticulation onto honeycomb. These films can be cured from temperatures as low as 180°F to as high as 350°F. Because these films are less messy and don't required mixing, they offer efficiencies in the design process. They are easier to use than typical paste adhesives.

See More 3M Structural Adhesive Films

3M is on the Leading Edge of Innovation
Adhesive bonding enables a more lightweight structure because it allows you to use more lightweight composite, as opposed to the metallic materials that were used in previous designs. Structural adhesive films are employed anywhere you are trying to bond metal to composite. This offers good erosion performance while minimizing weight.

Our Best for Your Best
3M is proud to partner with organizations across the spectrum of aerospace and related industries. Enabling efficiencies, reducing process times and lowering aircraft weight is how we execute our never-ending mission to offer best-in-class adhesives, sealants, surface protection products and composite resins that effectively reduce costs on multiple fronts. Professionals across the industry know the numerous advantages of 3M Aerospace. Our brand is widely recognized for the highest standards of quality and performance, adding value to the final results. By engineering reliability, longevity and value into all of our products, we have a history of saving money by reducing waste, rework and time.

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Typical properties