3M™ Dual Lock™ Reclosable Fastener SJ3550 250 Black, 1 in x 50 yd 0.22 in (5.6 mm), 2 per case Bulk

Strength in Numbers

One little mushroom won't accomplish much in this world, but pair him up with a few hundred of his friends and he becomes nearly unstoppable. Teamwork, that's the idea behind the design on our 3M™ Dual Lock™ Reclosable Fastener SJ3550. When joined together, our unique, mushroom-shaped stems combine to interlock with one another, generating five times the closure strength of typical hook and loop fasteners while maintaining the ability to easily peel-apart for quick access.

Our 3M™ Dual Lock™ SJ3550 Reclosable Fastener contains approximately 250 mushroom-shaped head stems per square inch. When two pieces of Dual Lock™ are pressed together the stems flex and the mushroom heads slide past each other. After mating, the stem snaps back into its original position, interlocking with the opposing heads with an audible snaps that signals the fastener is engaged. This system can be opened and closed 1,000 times while maintaining 50% of the original tensile strength.

No Drilling, Screwing, Tightening, or Complex Installation

Our Dual Lock™ SJ3550 uses an acrylic adhesive that bonds well to a variety of high medium surface energy materials, including some plastics, metal, glass, and painted surfaces. This ensures a quick and easy installation without the use of a mechanical attachment processes. The adhesive sticks quickly and reaches full strength after 72 hours. Once bonded the interlocked, mushroom-shaped stems may hold as well as screws and rivets, yet separates easily for access.

Versatile, Durable and Invisible

There's no limit to the number of uses for our Dual Lock™ fasteners. The stems, mushroom tops, and film backing are constructed of clear polypropylene, and the polyolefin backing resist common solvents and alkaline solutions, making them ideal for a variety of purposes and environments. The fastener is recommended for use at temperatures ranging from -20°F/-29°C to 200°F/93”C. Hidden from view when attached, these fasteners provide a clean, unbroken surface, and stay strong through more than 1,000 open-close cycles.

Dual Lock™ SJ3550 fasteners feature an acrylic foam tape protected by a removable liner. This construction allows for better contact with surfaces having a slight texture or surface irregularities.

To gain various levels of holding power, this fastener can be mated with different 3M Dual Lock Reclosable Fastener types. Suggested combinations of mated fasteners are:



Type 250 to Type 170

Type 250 to Type 250

Type 170 to Type 400

Type 250 to Type 400



For a quick grab attachment with high strength, but limited cycle life any of our 3M™ Dual Lock™ products can be mated with 3M™ Hook and Loop™ Reclosable Fasteners.