3M™ Dual Lock™ Introduction & Buying Guide



The Fastener

When two sides of 3M™ Dual Lock™ are pressed together, hundreds of mushroom-shaped stems interlock. "Snap" announces that the fastener is engaged. Compared to Hook & Loop the tensile strength is greater with 5x more holding power

Graphic closeup of 3M Dual Lock mushroom stem technology available from iTapeStore.com

Order your 3M™ Dual Lock™

Stem Count/Types

There are 3 basic types/stem counts of standard 3M™ Dual Lock™ with and without adhesive.

Type 250—Stems in Wave pattern, approximately 250 stems per inch.

Closeup Image of Type 250 stem count 3M Dual Lock available at iTapeStore.com

Type 170—wide rows, approximately 170 stems per inch.

Closeup Image of Type 170 stem count 3M Dual Lock available at iTapeStore.com

Type 400—heads almost touching, approximately 400 stems per inch.

Closeup Image of Type 400 stem count 3M Dual Lock available at iTapeStore.com

3M™ Dual Lock™ Stem Count/Mating Chart


170 to 250

Easy opening for multiple closures. Low engagement force, low tensile strength.


250 to 250 or 170 to 400

Most Common: Medium engagement force balanced with moderate tensile strength.


250 to 400

Higher engagement force balanced with high tensile strength.


Dual Lock to Loop fastener

Quick grab engagement, high peel force, very short cycle life


Adhesive Guide



SJ3560SJ3561SJ3562SJ4570SJ4575SJ4580SJ3870SJ3871 SJ3872
Bare Metals X X X X X X
Painted Metals X X X X   X
Fiberglass X X X X   X
Structural Composites X X X X    
Glass X X X X X  
Sealed Wood X X X X X X
Powdered Coated Paints X     X   X
Acrylic X X X X X X
Polycarbonate X X X X X X
Rigid Vinyl X X X X X X
Plasticized Vinyl   X X      
Polyethylene X      X   X (Primer Required)
Polypropylene X       X (Primer Required)
Polystyrene X     X X  
CARC Paint         X  
Alkyd Enamel Paint         X  
Painted Wood X       X  

*SJ3872 special order


3M™ Dual Lock™ ID Guide

Shop By the Yard, Trial Bags, Pre-cut Coins, Pre-cut Strips, EZpass Toll Strips, or you can email your product numbers, dimensions and quantity for pricing on cut to length or cut to shape parts to sales@iTapeStore.com.  Remember, quantity discounts show in cart, see our free ground shipping offer and New Jersey addresses will be charged sales tax.

Shop SJ3540, SJ3541, SJ3542


SJ3550CF 3Mtm Dual Locktm mated and opened


  • SJ3550CF, SJ3551CF, SJ3552CF - Clear, UV resistant, acrylic adhesive
  • Clear liner with red print
  • Black stems
  • Stem Count Guide/ID
Shop SJ3560, SJ3561, SJ3562


  • Clear liner with red print
  • Clear, UV resistant, acrylic adhesive
  • Clear stems
  • Stem Count Guide/ID
Shop SJ3870, SJ3871, SJ3572


  • Red liner
  • Black modified acrylic adhesive
  • Black stems
  • SJ3872 special order
  • Stem Count Guide/ID


Low Profile:

Shop SJ4570


  • Brown liner with green print
  • Clear acrylic adhesive
  • Clear stems
  • 705 stems per inch
  • Up to 24" wide
Shop SJ4575


  • Brown liner with green print
  • Clear acrylic adhesive
  • Black stems
  • 705 stems per inch
  • Up to 24" wide
Shop SJ4580


  • Red liner
  • Clear LSE acrylic adhesive
  • Clear stems
  • 705 stems per inch


Shop NO Adhesive


Shop SJ3440 Type 250, SJ3441 Type 400, SJ3442 Type 170


Shop SJ3460 Type 250


The following information is intended to assist the designer considering the use of 3M™ Dual Lock™ Reclosable Fasteners. Final product performance depends on actual conditions, including the fastener selected, the conditions in which the fastener is applied, the time and environmental conditions in which it is expected to perform. Because many of these factors are uniquely within the user's knowledge and control, it is required that the user evaluate the 3M™ product to determine whether it is fit for a particular purpose and suitable for the user's method of application and desired end use.

As a general rule, four square inches of fastener area per pound of static load to be supported is suggested as a starting point for evaluation. More or less area may be needed depending on specific conditions or end use applications.

Pressure Sensitive Adhesive attachment: The fasteners and substrate surfaces should have equilibrated for a minimum of 1 hour at temperatures of 68F (20C) or greater before application. Generally these adhesive backed fasteners should be applied to surfaces that are smooth, dry and free of oils, mold, release agents or other surface contaminants.

The substrate surface should be cleaned to remove any surface contaminants with an appropriate cleaning method for the customer's substrate, type and quantity of surface contaminants that need to be removed. Note: Be sure to follow all government regulations and the manufacturer's precautions and directions for use when using solvents or other cleaning methods.

After the substrate has been cleaned and dried, the liner is removed from the fastener's adhesive and without touching the adhesive, the fastener's adhesive is applied to the surface using light finger pressure. The fastener can then be rolled down, to increase contact of the adhesive with the substrate's surface, by one of two methods. Extra care must be exercised when rolling down 3M™ Dual Lock™ Reclosable Fasteners to prevent bending of the stems which can compromise the closure strength. The following methods allow adequate pressure to be applied to the Dual Lock™ without damaging the stems.

The first method uses a hand roller, with the roller wheel covered with a Type 170 3M™ Dual Lock™. The 3M™ Dual Lock™ covered roller is rolled over the 3M™ Dual Lock™ applied to the substrate, engaging and disengaging the two 3M™ Dual Lock™ pieces while being rolled down.

The pressure-sensitive adhesive bonds to the substrate on contact and parts can be handled immediately. Adhesive bond strength increases with time, pressure and temperature. A minimum of one hour dwell is recommended before applying a load or disengaging assembled parts. Recommended time to achieve maximum bond strength is 24 hours.

*The technical information is supplied by 3M™ and data should be considered representative or typical only and should not be used for specification purposes.