Shenzhen Karson Electronic Material Co., Ltd.
Shenzhen Karson Electronic Material Co., Ltd.

Shenzhen, Guangdong, China

Response Time: < 24h

Response Rate: 100%

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die cut no adhesive Dual Lock reclosable fastener 3M SJ3440

  • Min. Order:1 Meter(s)
  • Date of Delivery:3 days
  • Payment Type:L/C, D/A, D/P, T/T, Western Union, MoneyGram
  • Port:Shenzhen or Guangdong
Shenzhen Karson Electronic Material Co., Ltd.
Guangdong, China
  • Response Time: < 24h
  • Response Rate: 100%
Main Products: tape
Model No.: SJ3440 Brand: 3M Place of Origin: China
Packing: plastic film + carto... color: black adhesive: no adhesive

3M Dual Lock™ Reclosable Fasteners

None Adhesive Family

SJ3442 (Type 170)

SJ3440 (Type 250) SJ3460 Clear

SJ3441 (Type 400) SJ3461 Clear


3440 (4)

Product Description

3M™ Dual Lock™ Reclosable Fasteners consist of a continuous polyolefin film backing with mushroom shaped stems protruding up from the backing. When pressed together these mushroom shaped stems interlock to provide you with a strong reliable attachment. There are three different stem densities (170, 250 and 400) offered with these fasteners, referring to the approximate number of stems per square inch.

These 3M™ Dual Lock™ Reclosable Fasteners SJ3440, SJ3441, SJ3442, SJ3460 and SJ3461 have no adhesive backing and are used in specialty applications where unique attachment methods are necessary. 3M™ Dual Lock™ Reclosable Fasteners were developed and work best when held rigid and flat therefore all data provided in this document is typical data for when the product is securely anchored, held rigid and lays flat. The strength will vary depending on the applications and how well the fastener is attached. It is up to the end user to determine if this product meets the application needs.

These 3M™ Dual Lock™ Reclosable Fasteners can be mated in the following combinations of increasing closure strength: type 170 to type 250; type 170 to type 400 and type 250 to type 250 are about the same strength; and type 250 to type 400. For high tensile and shear strength applications, the 3M™ Dual Lock™ Reclosable Fasteners can combine with 3M™ Loop Fastener to form a limited use closure (about 25).


Black, interlocking mushroom-shaped heads (250 stem density per square inch) provide strong, reliable and durable fastening that can be opened and closed multiple times.

Mates with Type 170, Type 250 or Type 400 stem densities to provide different strength combinations.

Non-adhesive back for attachment with hot melt, epoxy or liquid adhesives.
Strong fastener secures with an audible snap, verifying closure.
An alternative to screws and bolts, this hidden fastener provides a snug fit and smooth aesthetic appearance.
Features good temperature resistance of 220°F (104°C), though temperature resistance may change based on adhesive used.
Suited for indoor or outdoor use.


3M™ Dual Lock™ Reclosable Fastener SJ3440 is the easy and clear alternative to traditional fastening methods, such as screws, nuts or bolts. It is designed to deliver a durable, reclosable fastening solution, which can be opened and closed multiple times. This black fastener is most commonly attached by applying hot melt, epoxy or liquid adhesive.

Unlock Simplicity 
Durable and secure, 3M™ Dual Lock™ Reclosable Fastener SJ3440 has exceptional strength through its interlocking mushroom-shaped heads (250 stem density per square inch). With 3M™ Dual Lock™ Reclosable Fastener SJ3440, there is no need for any drilling or screwing. This fastener is most commonly attached by applying hot melt, epoxy or liquid adhesive. 

Recommended Applications:

  • Alternative to pressure sensitive adhesives

Product Construction

Note: The following technical information and data should be considered representative or typical only and should not be used for specification purposes.

Product Number(Black)SJ3442SJ3440SJ3441
Type: Approx.Stems/In2 (Stems/cm2)170 (26)250 (39)400 (62)
Material of Construction---polyolefin blendpolyolefin blendpolyolefin blend
Thickness ± 10%Unmated:0.101 inch (2.57 mm)0.101 inch (2.57 mm)0.101 inch (2.57 mm)
Engaged:0.152 inch (3.86 mm)0.152 inch (3.86 mm)0.152 inch (3.86 mm) 
Closure Cycle Life *---1,0001,0001,000
* Number of opening and closings before losing 50% of original tensile strength
SHELF LIFE 24 months from mfg. date when stored at 72F with 50%RH

Design Considerations

The following information is intended to assist the designer considering the use of 3M™ Dual Lock™ Reclosable Fasteners. Product performance depends upon a number of factors, including the 3M™ Dual Lock™ Reclosable Fastener selected, the manner in which reclosable fastener is attached, and the time and environment 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 3M products to determine whether it is fit for a particular purpose and suitable for the users substrates, method of application and desired end use.

It is suggested that 4 square inches of 3M™ Dual Lock™ Reclosable Fasteners per 1 pound of static load be used as a starting point when determining how much 3M™ Dual Lock™ Reclosable Fasteners to use on any particular application. The amounts may be adjusted up or down depending on the needs of the specific applications.


To Chemicals: The polyolefin backing stems and mushroom top should resist attack by most common solvents and alkaline solutions.
To Environmental Exposure: Temperatures between -20°F (-29°C) and and 220°F (104°C) should have minimal effect on closure strength. To maintain performance when exposed for extended periods to sunlight or ultraviolet radiation these products should be placed between two opaque or UV resistant surfaces. Specific testing under the expected environmental conditions is recommended.
To Water or Humidity: Closure strength should not be affected by prolonged exposure to water or humidity.

The important link:

        Design Selection Guide

the guide will show you that how to choose 3M fasteners.

Our Service:

(1) Slitting: any width any length





(2) Die Cutting: any shape any size


die cutting.gif



About us:

We have been selling original 3M products ( VHB tapes, Double coated foam tapes, Double coated adhesive transfer tapes, Double coated removable repositionable tapes, Automotive attachment tapes, Single coated foam tapes, Reclosable Mushroom-heads fasteners ) for many years, we have a professional die cut factory in Shenzhen.


We make orders at Alibaba platform, its TRADE ASSURANCE protect your order from payment to delivery.


Don't worry the quantity of your order, we will try our best to help you.


Any question about 3M products, please contact us simply leave me message at Alibaba platform or by my Mobile / Skype / Wechat / Whatsapp: +86-13632581926.

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Contact Details

George Lee

George Lee






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