3M™ Dual Lock™ Reclosable Fastener SJ3719, Pop-In Piece Part, Stem Density 250, Black

3M™ Dual Lock™ Reclosable Fastener SJ3781 is a polypropylene reclosable fastener with a pop-in square top, a rectangular base and a stem density of 250 stems per square inch. Dual Lock reclosable fastener SJ3781 overcomes the often difficult alignment and installation problems of screws and hidden fasteners, offering simple installation without requiring the use of special tools. 3M™ Dual Lock™ Reclosable Fasteners are positive-locking, blind fasteners designed for attaching automotive trim components. The products feature mushroom-shaped polyolefin stems that snap together, forming a high tensile closure. Dual Lock fasteners are used primarily to secure rigid and semi-rigid surfaces such as trim or door panels, instrument panel bezels, headliners, and other automotive interior and exterior trim.

3M™ Dual Lock™ Reclosable Fasteners Pop-In Parts attach without the use of pressure sensitive adhesive, and come with a variety of bases that can be inserted into holes of precise dimension. They are easy to install and require no special equipment or skills.

How It Works
When two pieces of 3M™ Dual Lock™ Reclosable Fasteners are pressed together, the stems flex and the mushroom heads slide past each other. After passing the opposing mating piece, the stems snap back into their original position and the opposing mushroom heads interlock. These fasteners can provide high tensile strength but can be opened by simply cleaving or peeling open the closure.

Alignment and re-alignment are easy and no special tools are required for installation. Dual Lock fasteners can be used to attach components before they enter the final assembly plant, helping to reduce the number of parts and assembly time.

Stem Densities
Combinations of stem densities and the engaged area provide adjustable and proportional engagement and disengagement force to meet application needs. Dual Lock fasteners are offered in three different densities (stems per square inch): 170, 250, and 400. Our Dual Lock fastener SJ3209 has 250 stems per square inch and mates to Type 170, 250 or 400. Types 170 and 400 should not be mated with another fastener of the same density.

Recommended Applications
3M™ Dual Lock™ Reclosable Fasteners can replace conventional mechanical fasteners in a wide range of assembly and attachment applications where reclosability or serviceability is desired. Dual Lock fasteners are used primarily to secure rigid and semi-rigid surfaces such as trim or door panels, instrument panel bezels, headliners, and other automotive interior and exterior trim. Some examples of applications include:

• Vehicle headliners
• Attaching accessories and equipment
• Attaching window and door trim panels
• Vibration and sound damping control
• CHMSL cover plates
• Center console flanges
• Interior trim
• Sunroof rings

3M Science Delivers Closures You Can Count On
3M™ Dual Lock™ Reclosable Fastener are ideal for many applications where a high strength, reclosable fastening system is required. 3M engineers have uniquely combined physics and materials science to bring the automotive industry reliable fasteners that supply high performance even after exposure to high moisture levels and wide temperature ranges. For applications that require a pop-in piece and multiple closures, look no further than the long-lasting durability of our 3M™ Dual Lock™ Reclosable Fastener SJ3719. It is yet another outstanding example of how 3M technologies advance operations in the automotive industry, providing both ease of use and superior results.

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