3M™ Dual Lock™ Reclosable Fastener SJ3222, Pop-in Piece Part, StemDensity 250, Black, 700 Piece/Case

3M™ Dual Lock™ Reclosable Fastener SJ3222 is a black, polyolefin reclosable fastener with a unique pine tree shaped base and a 26 mm square top. It has a stem density of 250 stems per square inch and securely fits into a 7 mm round hole. This fastener is designed to attach pop-in parts without the use of pressure sensitive adhesive. It comes with a variety of bases that can be inserted into holes of precise dimensions. Installation is easy and does not require any special equipment or skills.

This fastener solves the common problems of alignment and installation that are often encountered with screws and hidden fasteners. It offers a simple installation process without the need for special tools. 3M™ Dual Lock™ Reclosable Fasteners are blind fasteners that are specifically designed for attaching automotive trim components. They feature a pine-tree-shaped polyolefin base and a square top with mushroom shaped stems that 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.

How It Works
This pop-in fastener is designed to be inserted into a slot of a specific dimension where attachment is desired. Its polypropylene disk base grips the inside of the hole tightly. The fastener can then be mated and engaged to a second Dual Lock fastener attached to a piece of trim or another part, firmly securing the parts together.

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 provide high tensile strength but can be easily opened by cleaving or peeling open the closure.

Alignment and re-alignment are easy, and no special tools are required. This means that they can be used to attach components before they enter the final assembly plant, reducing 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. Dual Lock fastener SJ3222 has 250 stems per square inch, offering a secure hold, and can be mated to Type 170 or 400. It should not be mated with another Type 250 fastener that is less than 3/4 inch.

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 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. 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