Dual Lock™
Fastening System
Product Data Sheet Updated : April 1999
Supersedes : June 1995
Product Description Dual Lock™ fastener is a
reclosable fastening system
where mushroom shaped
stems interlock with one
another when pressed
together.
Available in 25mm black or
clear, plain backed or with
rubber or acrylic self-
adhesive backing, giving
1000+ closures.
Product Number Backing Attachment Operating Temperature Features
SJ3440, Type 250 stems
SJ3441, Type 400 stems
SJ3442 Type 170 stems
Plain-backed.
Sew on or staple. -20°F - 158°F continuous
-20°F - 200°F intermittent
Wash or dry clean.
SJ3540, Type 250 stems
SJ3541 Type 400 stems
SJ3542 Type 170 stems
Pressure sensitive rubber
adhesive -20°F - 158°F continuous
-20°F - 120°F intermittent
with no static load.
General purpose.
Bonds to most surfaces.
SJ3550, Type 250 stems
SJ3551 Type 400 stems
SJ3552 Type 170 stems
Pressure sensitive very high
bond VHB™ acrylic
adhesive.
-20°F - 158°F continuous
-20°F - 200°F intermittent
High performance for aircraft,
automotive, business
equipment, electronics.
Resists harsh wet/dry,
Hot/cold cycles.
SJ3560 Type 250 stems Clear, pressure sensitive
very high bond VHB™
acrylic adhesive.
-20°F - 158°F continuous
-20°F - 200° intermittent
UV Resistant.
Plasticiser Resistant.
2
Date : April 1999
Dual Lock Fastening System
Performance
Characteristics
Dynamic Performance :
Closure Combination of Types
Property Surface 170 to 400 250 to 250 250 to 400 400 to 400 170 to loop 250 to loop
Tensile
disengagement
Lbs/sq.in.
(kPa)
Rigid
to
Rigid 32
(221)
Clear
38
(262)
Black
30
(207) 47
(324) 55
(380)
Peel Strength
Lbs/sq.in.
(N.100mm)
Rigid
to
Flexible 10
(175) 8
(140)
Fastener combinations were mated, then disengaged at a rate of 12 inches (305mm)/minute. Tests were conducted under controlled laboratory
conditions at 72°F (22°C), 50% R.H.
Static Performance : Closure Combination of Types
Property Temperatures 170 to 400 250 to 250 250 to 400 400 to 400
Static Shear.
Gram/sq.in. will hold listed
weight for 10,000 minutes.
-20°F (-29°C)
72°F (22°C)
200°F (93°C)
1,000
1,000
500
1,000
1,000
500
1,000
1,000
500
1,000
1,000
500
Static Tensile.
Gram/sq.in. will hold listed
weight for 10,000 minutes.
-20°F (-29°C)
72°F (22°C)
200°F (93°C)
1,000
1,000
500
1,000
1,000
500
1,000
1,000
500
1,000
1,000
500
Fasteners were attached to metal panels and engaged in the combinations listed. Tests were conducted at the temperatures and gram loadings
listed. Tests were discontinued after 10,000 minutes (7 days).
Static Performance : Adhesive Bond
Property Temperatures SJ3540/41/42 SJ3550/51/52 SJ3560
Static Shear.
Gram/sq.in. will hold listed
weight for 10,000 minutes.
-20°F (-29°C)
72°F (22°C)
120°F (49°C)
200°F (93°C)
1,000
1,000
500
-
1,000
1,000
1,000
500
1,000
1,000
1,000
500
Static Tensile.
Gram/sq.in. will hold listed
weight for 10,000 minutes.
-20°F (-29°C)
72°F (22°C)
120°F (49°C)
200°F (93°C)
1,000
1,000
500
-
1,000
1,000
1,000
500
1,000
1,000
1,000
500
Fasteners were attached to aluminium and stainless steel panels and engaged in the combinations listed. Tests were conducted at the
temperatures and gram loadings listed. Tests were discontinued after 10,000 minutes (7 days).
NOTE: In static load applications, conditions such as temperature variation, vibration, jarring, etc. Can affect long term performance. The user
should design the amount of fastening area based on specific conditions in the application. Four square inches of fastening area per pound of
static load is suggested as a starting point for evaluation.
3
Date : April 1999
Dual Lock Fastening System
Physical Properties
Contd . . . Not for specification purposes
Plain-Backed Pressure Sensitive Adhesive-Backed
Properties SJ3440 SJ3441 SJ3442 SJ3540 SJ3541 SJ3542 SJ3550 SJ3551 SJ3552 SJ3560
Weight
g/25mm x
25mm 0.5 0.5 0.4 0.7 0.7 0.6 0.9 0.9 0.9 1.1
Colours Black Black Black Black Black Black Black Black
White
Adhesive
Black
White
Adhesive
Clear
Clear
Adhesive
Liner None None None White
Poly-
ethylene
White
Poly-
ethylene
White
Poly-
ethylene
Red
Poly-
ethylene
Red Poly-
ethylene Red
Poly-
ethylene
Red
Poly-
ethylene
Preferred
Mating
Fasteners
SJ3440
SJ3540
SJ3550
SJ3442
SJ3542
SJ3552
SJ3441
SJ3541
SJ3551
Scotch-
mate
loop
SJ3440
SJ3540
SJ3550
SJ3442
SJ3542
SJ3552
SJ3441
SJ3541
SJ3551
Scotch-
mate
loop
SJ3440
SJ3540
SJ3550
SJ3442
SJ3542
SJ3552
SJ3441
SJ3541
SJ3551
Scotch-
mate
loop
SJ3560
Engaged
Thickness mm
SJ3440
SJ3540
SJ3550
SJ3560
SJ3441
SJ3541
SJ3551
SJ3442
SJ3542
SJ3552
Scotchmate
plain loop
PSA
4.1
4.6
4.1
4.8
4.8
4.1
4.8
4.8
3.8
4.1
5.8
4.8
5.8
5.8
4.1
4.8
4.8
3.8
4.1
5.8
4.6
5.6
4.8
5.8
5.8
4.8
5.3
4.6
4.8
5.8
5.8
5.8
5.8
Shelf Life * 1 year 1 year 1 year 1 year 1 year 1 year 1 year 1 year 1 year 1 year
* 12 months from date of despatch by 3M when stored in original packaging at 70°F (21°C).
4
Date : April 1999
Dual Lock Fastening System
Attachment/Application Pressure-sensitive: Apply
above 20°C. Surface must
be clean, dry and free from
oil. Allow 48 hours
(SJ3541/2) or 72 hours
(SJ3551/2) for maximum
bond strength. Improved
resistance to edge peel can
be provided by recessing
the Dual Lock fastener, or
by rounding the corners. In
some exceptional cases
(contamination by mould
release, rough or porous
surfaces etc) it may be
necessary to sand or abrade
the surface, or use an
adhesive primer to optimise
bond performance.
Mechanical Attachment:
Staples or other methods of
mechanical attachment may
be used either alone
(SJ3441/2) or in conjunction
with the pressure sensitive
adhesive (SJ3541/2,
SJ3551/2) to give additional
holding strength, particularly
at elevated temperatures or
on rough or porous
surfaces.
Ultrasonic Sealing: May be
used to permanently fuse
non-adhesive products
(SJ3441/2) to themselves or
polypropylene surfaces in
about one second.
Sewing: Use extra strong
nylon, cotton-covered
polyester, or waxed cotton
thread as for buttons,
carpets, or very heavy
fabrics. Sew along all
edges with a two-thread
lock stitch, using 6-8
stitches per inch, or use a
box stitch.
Product Information Backing/Substrate Selection
Plain-Backed
Sew-On
Pressure-Sensitive Adhesive Backed
Substrates SJ3440 SJ3441 SJ3442 SJ3540 SJ3541 SJ3542 SJ3550 SJ3551 SJ3552 SJ3560
Bare Metal üüüüüü ü
Painted Metal üüüüüüü
Finished Wood üüüüüüü
Plastics : ABS üüüüüüü
Polystyrene üüüüüüü
Acrylic üüüüüüü
Polyethylene üüü
Polypropylene üüüüüü
Polycarbonate üüüüüüü
Rigid Vinyl üüüüüüü
Plasticised
Vinyl
üüü üüüü
5
Date : April 1999
Dual Lock Fastening System
Product Information Backing/Substrate Selection
Plain-Backed
Sew-On
Pressure-Sensitive Adhesive Backed
Fabrics üüü
Leather üüü
Paper, cardboard üüüüüüü
Rubber üüü
Glass üüüüüüü
Painted Concrete üüüüüüü
3M, Dual Lock, Scotchmate and VHB are trademarks of the 3M Company.
Values presented have been determined by standard test methods and are average values not to be used for specification purposes.
Our recommendations on the use of our products are based on tests believed to be reliable but we would ask that you conduct your own tests to
determine their suitability for your applications.
This is because 3M cannot accept any responsibility or liability direct or consequential for loss or damage caused as a result of our
recommendations.
Tapes & Adhesives 3M United Kingdom PLC 1996
3M United Kingdom PLC
3M House,
28 Great Jackson Street,
Manchester,
M15 4PA
Customer Service :
Tel [3MUKP1]0161 236 8500
Fax 0161 237 1105
3M Ireland
3M House, Adelphi Centre,
Upper Georges Street,
Dun Laoghaire,Co. Dublin,
Ireland
Customer Service :
Tel (01) 280 3555
Fax (01) 280 3509
Page: 5
[3MUKP1]
