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  6. 3M™ Dual Lock™ Reclosable Fastener SJ3870

3M™ Dual Lock™ Reclosable Fastener SJ3870

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Snap-in-place installation replaces screws, nails, snaps and rivets

Five times the tensile strength of typical hook-and-loop fasteners

Durable — up to 1,000 openings and closings before losing 50 % of original tensile strength

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Tech Data Sheet (PDF, 677KB)


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  • Snap-in-place installation replaces screws, nails, snaps and rivets
  • Five times the tensile strength of typical hook-and-loop fasteners
  • Durable — up to 1,000 openings and closings before losing 50 % of original tensile strength
  • Features excellent heat resistance up to temperatures of 82 °C
  • Black, interlocking mushroom-shaped heads (250 stem density per 6.5 cm²)
  • Ideal for indoor and outdoor use to attach doors, flexible solar panels, headliners, access panels, signs and display components
  • Helps reduce vibration
  • Suitable for both indoor and outdoor use

3M™ Dual Lock™ Reclosable Fastener SJ3870 has a modified acrylic adhesive on the back of a black polypropylene reclosable fastener. Our product can be used both indoors and outside in a variety of applications; and has a slim 6.1 mm engaged thickness and long service life.

Our remarkable 3M™ Dual Lock™ Reclosable Fastener SJ3870 can be opened and closed over and over, up to 1000 times before losing 50% of the original strength for repeated access or repositioning. The mushroom heads easily slide over each other allowing positioning of parts before they are snapped together to create a firm fastening attachment. When mated, the fasteners are hidden from view and leave you with an unbroken surface to help create a smooth, clean appearance. The Type 250 stem density polyolefin fastener mates to Type 170, 250 or 400 giving the user the option of different closure strength depending upon applications. Recommended applications are general industrial, transportation, specialty vehicle, medical military packaging, point of purchase displays, exhibits, electronics, construction, furniture, and maintenance repair and operations (MRO). This fastener is backed by a modified acrylic adhesive that bonds to many plastics (polyethylene, acrylic, polycarbonate and ABS), powder coated paints and medium to low surface energy materials with little or no surface preparation. Hear the snap “Snap!” It’s the one word that best defines 3M’s extensive line of Dual Lock™ products. Here’s how it works - when two pieces of 3M™ Dual Lock™ Reclosable Fastener are pressed together, the stems flex and the mushroom heads slide past each other. After passing the mushroom heads on the opposing mating piece, a stem snaps up into its original position, interlocking with the opposing heads. Listen for the audible snap to signal that the fastener is engaged. The attachment formed may be as effective as screws or rivets, but will peel apart for repositioning. 3M Dual Lock Reclosable Fasteners are used extensively in transportation, electronics, business equipment, machinery, medical, and sign and display markets. Lose the Screws The bond is strong but can easily be detached; just pull apart to disengage and reattach as needed. This means that this product gives you a strong, hidden closure with the convenience of multiple openings and closings so you can lose the screws, rivets, hooks, bolts, zippers and other unsightly attachment methods. In short – this product is an aesthetically pleasing fastener that doesn’t sacrifice attachment strength; in fact, SJ3870 is about five times stronger in tensile strength than 3M™ Hook and Loop fasteners used in comparable applications. In many cases, this attachment method also saves the user money with less material used. Additionally, there’s no need to drill holes that might weaken the part or substrate, and no tools required to assemble and remove the part. Expect more options to secure, attach and connect surfaces - 3M Dual Lock Reclosable Fasteners offer quick installation and high-strength attachment, yet can be opened as easily as zippers. Functional flexibility, as well as superior aesthetics, reduced weight, and savings in labour and installation costs, make 3M’s innovative fasteners a popular and effective solution.

Suggested applications
  • Panel and cover plate attachment
  • Interior signage
  • Decorative trim
  • Office partitions
  • Graphic attachment
  • Access panels
  • Specialty vehicles (interior attachments)
  • L-bracket edging, repositionable shelving
  • Hang signage

Typical Properties


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Similar products

Overall Width (Metric) 25.4 mm, 25 mm
Product Form Roll
Backing (Carrier) Material Polypropylene
Product Colour Black
Adhesive Type Modified Acrylic