3M™ Dual Lock™ Reclosable Fastener SJ3803, Slide-in Piece Part, Stem Density 250, Black, 20 mm x 39.5 mm

Designed to Hold

The 3M Dual Lock Reclosable Fastener SJ3803 is a black, polypropylene reclosable fastener with a 20 mm x 40 mm base, extended edges, and a density of 250 stems per square inch. This innovative product solves the common challenges of aligning and installing screws and hidden fasteners, offering a simple installation process that requires no additional tools. Specifically designed for attaching automotive trim components, the Dual Lock fasteners feature mushroom-shaped polyolefin stems that securely snap together, creating a high tensile closure. These fasteners are primarily used to secure rigid and semi-rigid surfaces such as trim or door panels, instrument panel bezels, headliners, and other automotive interior and exterior trim. Unlike pressure-sensitive adhesive fasteners, the Dual Lock fasteners attach without the need for adhesive and come with a variety of bases that can easily slide into holes of precise dimensions. With their easy installation and no special equipment or skills required, these fasteners are a convenient solution for various automotive applications.

How It Works

The 3M Dual Lock Reclosable Fastener SJ3803 is designed to be inserted into a same-width channel where attachment is desired. The polypropylene extended edges of the base securely grip the inside of the channel, ensuring a tight hold. The fastener can be mated to a second Dual Lock fastener attached to a piece of trim or another part, resulting in a firm and secure connection between the two parts. When two pieces of Dual Lock fasteners are pressed together, the stems flex and the mushroom heads slide past each other. Once they pass the opposing mating piece, the stems snap back into their original position, and the opposing mushroom heads interlock. These fasteners provide high tensile strength but can be easily opened by cleaving or peeling open the closure. The Dual Lock fastener allows for easy alignment and re-alignment without the need for special tools, making it suitable for attaching components before they enter the final assembly plant, reducing the number of parts and assembly time.

Stem Densities

The stems of the Dual Lock fasteners offer more strength than traditional hook and loop closures while still allowing for easy peeling apart. The combination of stem densities and the engaged area provides adjustable and proportional engagement and disengagement force to meet specific application requirements. The Dual Lock fasteners are available in three different densities: 170, 250, and 400 stems per square inch. The SJ3803 model, specifically, has 250 stems per square inch (25mm), offering a tight hold and can be mated to Type 170, 250, or 400 fasteners.

Recommended Applications

The 3M Dual Lock Reclosable Fasteners are a versatile alternative to conventional mechanical fasteners in a wide range of assembly and attachment applications where reclosability or serviceability is desired. In addition to securing automotive trim components, these fasteners can be used for attaching accessories and equipment, window and door trim panels, sunroof rings, and vibration and sound damping control. Their reliable performance, even after exposure to high moisture levels and wide temperature ranges, makes them ideal for applications that require a slide-in piece and multiple closures. The 3M Dual Lock Reclosable Fastener SJ3803 exemplifies the durability and effectiveness of 3M technologies in advancing operations in the automotive industry, providing both ease of use and superior results.