3M SJ3551 Dual Lock 400 Reclosable Fastener is a general-purpose black reclosable fastener with 400 stems per square inch, an engaged thickness of 0.23 inches and a closure life of 1,000. This black fastener has mushroom-shaped stems on a polypropylene carrier which is coated with a white, general-purpose acrylic pressure-sensitive adhesive.
Type 400 stem density fasteners can mate to type 170, 250 or 400 fasteners (the higher the combined number the greater the closure strength). Mushroom-shaped stems on one side of the fastener interlock with identically shaped stems on the other side for 5X greater closure strength than hook and loop.
Dual lock type 400 fasteners are designed to bond to metals, glass, and medium-to-high surface energy plastics and paint. They can replace conventional fasteners such as screws, clips, rivets, snaps, hook and loop and bolts in many applications where access or repositioning is needed.
** This sometimes now ships as SJ3551CF which has the same product specifications but has a clear release liner instead of a white 3M release liner.
Engaged Thickness: 230 mils. Pins: 400 per square inch. Carrier/Backing: polypropylene. Adhesive: acrylic (300 LSE). Release Liner: clear polyolefin film. Thickness: 140 mils (carrier, adhesive) 4 mils (liner). Service/Operating Temperature: up to 200F.