Standard anaerobic threadlockers (Dri-Loc family) cure by oxygen exclusion — the anaerobic environment created when threads engage triggers the cure. ND Industries adhesives use a different trigger: microcapsules containing the adhesive components are coated onto the fastener thread. The capsule walls are intact and the adhesive is inert in storage. When threads engage at assembly, the shear force crushes the capsule walls, releases the adhesive, and room-temperature cure begins. No oxygen exclusion required.

This microencapsulated mechanism has practical advantages for certain substrates and assembly conditions where anaerobic cure can be inhibited or inconsistent. The adhesives cure on a wide range of metal substrates, remain dormant indefinitely in storage, and arrive at the assembly station dry to the touch.

Expand-A-Lock is unique even within the ND family: unlike the 593S and 1193S grades which fill thread voids like conventional threadlockers, Expand-A-Lock increases in volume 20 to 50% on cure, actively penetrating gaps and voids that conventional threadlockers cannot reach. Specified for engine pipe plugs, air fitting connectors, compressor fittings, and cooling connectors — critical applications where conventional gap-fill is not sufficient.