3M™ Dual Lock™ SJ3552 Reclosable Fastener

3M™ Dual Lock™ SJ3552 Reclosable Fastener: High-performance removable fastening

The 3M™ Dual Lock™ SJ3552 is a reclosable fastener designed for strong removable attachments, without the need for screws or permanent glue.

Its system of interlocking mushroom-shaped stems generates high holding power while allowing for quick and repeated removal.

Ideal for demanding industrial environments, it resists vibration, moisture, and extreme temperatures.

Available from Dagobert Industrie, this 3M tape is compatible with a wide range of surfaces and applications.

What is the 3M™ Dual Lock™ SJ3552 reclosable fastener?

The 3M™ Dual Lock™ SJ3552 is a removable mushroom-stem fastener tape. It is a mechanical attachment system that effectively replaces screws, rivets, or permanent adhesives in many industrial applications.

The SJ3552 comes as a flexible black polypropylene tape with a repositionable acrylic adhesive backing. It sticks directly to the surface to be fastened, without tools or drilling.

How Dual Lock™ mushroom stems work

Unlike traditional Velcro® (hook & loop), the Dual Lock™ system works identically on both sides: each side features mushroom-shaped stems. Two sides lock together with simple pressure.

Engagement produces an audible click, confirming the attachment. Separation is achieved by progressive peeling, without damaging the surfaces or leaving residue.

The SJ3552 has a density of 250 stems per sq in, providing excellent shear strength while remaining easily removable by hand.

Part Number	Stem Density (per sq in)	Shear Strength	Adhesive Backing	Typical Use
3M™ Dual Lock™ SJ3552	250	High	Acrylic	Light to medium industrial fastening
3M™ Dual Lock™ SJ3550	170	Medium	Acrylic	Light assembly, prototyping
3M™ Dual Lock™ SJ3560	400	Very high	Reinforced acrylic	Heavy-duty fastening, vibrations
Industrial Velcro® (hook/loop)	-	Low to medium	Variable	Textile, packaging, general use

Technical specifications and typical properties of the SJ3552

The 3M™ Dual Lock™ SJ3552 is a reusable mechanical fastening tape. It works without hooks or loops: two identical sides interlock via rigid polypropylene mushroom stems.

The stem density of the SJ3552 is 400 stems/sq in. This is the intermediate density in the Dual Lock range, between the SJ3550 (170 stems/sq in) and the SJ3560 (250 stems/sq in). The higher the density, the greater the shear strength.

The backing is a black polyester film, resistant to UV and temperature variations. The operating range is generally -40°C to +70°C, making it suitable for demanding industrial environments.

The back of the tape is equipped with a high-performance acrylic adhesive. It bonds to most clean, dry, and smooth surfaces: metal, ABS plastic, polycarbonate, glass.

Part Number	Density (stems/sq in)	Backing	Typical Use
SJ3550	170	Black polyester film	Light fastening, frequent access
SJ3560	250	Black polyester film	General use, moderate cycles
SJ3552	400	Black polyester film	High-strength fastening, repeated cycles
Velcro® PS14	N/A (hook/loop)	Nylon	Textile, general use

Unlike traditional Velcro® (hook + loop), the Dual Lock SJ3552 does not clog as easily and supports more opening/closing cycles without significant performance loss.

Comparison: 3M™ Dual Lock™ SJ3552 vs. other removable fastening systems

The removable fastener market offers several solutions: industrial Velcro, rivets, magnets, screws… Each system has its limits. The 3M™ Dual Lock™ SJ3552 stands out for its combination of strength, repeatability, and discretion that is hard to match.

Unlike standard Velcro (hook/loop), Dual Lock™ works with two identical mushroom-stem strips. Both sides assemble with each other, which simplifies stock management and eliminates installation errors.

Comparison table: SJ3552 vs. other Dual Lock™ references and industrial Velcro

Product	Type	Stem Density	Shear Strength	Opening/Closing Cycles	Typical Use
3M™ Dual Lock™ SJ3552	Mushroom stems	400 stems/sq in	High (~3.5 N/cm²)	~1,000	Industrial fastening, panels, equipment
3M™ Dual Lock™ SJ3550	Mushroom stems	250 stems/sq in	Moderate (~2.5 N/cm²)	~1,000	Light assembly, signage
3M™ Dual Lock™ SJ3560	Mushroom stems	570 stems/sq in	Very high (~5 N/cm²)	~500	Heavy-duty fasteners, high vibration
Industrial Velcro® (hook/loop)	Hook + loop	N/A	Low to moderate	>5,000	Textile, cabling, light assemblies

The SJ3552 occupies an ideal intermediate position: more efficient than the SJ3550, more durable in cycles than the SJ3560. It is the balanced choice for most common industrial applications.

Compared to standard Velcro, the advantage is clear: no clogging by dust, superior mechanical resistance, and a stiffer profile that is suitable for flat and rigid surfaces.

Applications and fields of use for the Dual Lock™ SJ3552 tape

The 3M™ Dual Lock™ SJ3552 reclosable fastener is designed for removable and repeatable fixings in demanding environments. Its interlocking mushroom structure offers a firm hold without permanent glue.

This tape is used wherever a component must be fastened, removed, and refastened quickly. It effectively replaces screws, rivets, or clips in many configurations.

Here are the main fields of application:

• Automotive industry: fastening door panels, interior trim, onboard electronic boxes
• Electronics and telecommunications: mounting cards, screens, or control housings
• Display and signage: mounting and removing panels, POS, communication media
• Furnishings and furniture: fastening shelves, covers, removable facades
• Transport and logistics: securing equipment in vehicles subject to vibrations

The SJ3552 stands out for its high resistance to vibration and impact. It is particularly suitable for flat or slightly curved surfaces, indoors and in protected outdoor areas.

Its acrylic adhesive backing ensures durable adhesion on metal, plastic, and composites without complex surface preparation.

Product	Type	Stem Density	Shear Resistance	Typical Usage
3M™ Dual Lock™ SJ3552	Male/Male stems	400 stems/sq in	High	Industrial, auto, electronic fastening
3M™ Dual Lock™ SJ3550	Male/Male stems	170 stems/sq in	Moderate	Light fastenings, signage
3M™ Dual Lock™ SJ3560	Male/Male stems	400 stems/sq in	High	Outdoor, reinforced UV resistance
Industrial Velcro® (hook & loop)	Hook/loop	N/A	Low to moderate	General, textile, light

Application tips and surface compatibility for the SJ3552

The SJ3552 adheres to most smooth, rigid, and clean surfaces. ABS plastic, painted metal, glass, polycarbonate: the results are reliable provided a few simple steps are followed.

Before application, thoroughly degrease the surface with isopropanol or a 3M cleaner. Any trace of oil, dust, or moisture significantly reduces adhesion.

Apply the tape by exerting firm and uniform pressure along its entire length. An application roller or your thumb is sufficient. Avoid air bubbles under the adhesive backing.

Allow a 24-hour activation time before initial mechanical loading. The acrylic glue of the SJ3552 increases in strength progressively after application.

The SJ3552 is not suitable for porous surfaces (raw wood, untreated concrete, foam) or highly textured surfaces. Adhesion will be insufficient on these substrates.

For surfaces with low surface energy like polypropylene or polyethylene, use a 3M adhesion promoter (such as Primer 94) before application to ensure hold.

Both Dual Lock strips must be aligned face-to-face before interlocking. Misalignment reduces engagement force and causes premature wear on the mushroom stems.

When removing, slowly peel the tape at a shallow angle (180°) to limit the risk of tearing on fragile surfaces. A low-temperature heat gun facilitates detachment.

FAQ - 3M™ Dual Lock™ SJ3552 Reclosable Fastener

1. What is the difference between the Dual Lock™ SJ3552 and classic Velcro?

The Dual Lock™ SJ3552 uses rigid polypropylene stems that interlock with each other, unlike Velcro which combines flexible hooks and loops.

Result: significantly higher shear resistance and a more uniform hold over the entire contact surface.

2. Is the SJ3552 usable outdoors?

Yes. The SJ3552 is resistant to UV, moisture, and temperature variations, making it suitable for outdoor applications.

Its high-performance acrylic adhesive bonds to painted, plastic, or metallic surfaces, even when exposed to the elements.

3. How many times can the fastener be opened and closed?

The Dual Lock™ SJ3552 supports more than 1,000 opening/closing cycles without significant performance loss.

This is a key advantage for applications requiring regular access, such as signage panels or maintenance equipment.

4. Do I need two SJ3552 strips face-to-face for it to work?

No. This is one of the great strengths of the Dual Lock™ system: a strip fastens to itself. The stems of the SJ3552 lock onto those of another SJ3552 strip, but also onto those of other compatible references in the range.

Only one part number to manage for both sides of the assembly.

5. On what types of surfaces does the adhesive hold correctly?

The adhesive works well on smooth, clean, and degreased surfaces: metal, rigid plastic, glass, lacquered wood.

On porous or textured surfaces, the hold is reduced. Cleaning with isopropanol before application significantly improves adhesion.

6. Can the SJ3552 replace screws or rivets in some cases?

Yes, in many configurations. The Dual Lock™ SJ3552 allows fastening without drilling, which preserves material integrity and simplifies assembly.

It is used in particular to fasten automotive interior trim, electronic panels, or industrial signage plates.