Full definition
A two-component (resin + hardener) structural adhesive providing the highest shear and tensile strength (15-45 MPa) of any industrial adhesive family, along with excellent chemical resistance and temperature stability. When mixed, the epoxy resin and amine or polyamide hardener undergo an exothermic cross-linking reaction producing a rigid, thermoset polymer. Cure speed grades: 5-minute (rapid prototyping), 30-minute (general assembly), 60-minute (positioning time for large assemblies), and 24-hour (maximum strength and chemical resistance). Temperature resistance: 80-120°C (standard amine), 150-200°C (anhydride-cured or high-performance). Bonds: metals, ceramics, glass, wood, concrete, and many plastics (not polyethylene/polypropylene without flame/plasma treatment). Mix ratios: typically 1:1 or 2:1 by volume. Limitations: rigid — poor at absorbing dynamic loads and thermal cycling (use PU for flexible bonds); brittle in peel; exothermic — thick sections can overheat. Specialty formulations: toughened (improved peel and impact), conductive (silver-filled, for electronics), and underwater (cures submerged). Per ASTM D1002 (lap shear), ASTM D2095 (tensile). Brands: Loctite Hysol (Henkel), 3M Scotch-Weld, Araldite (Huntsman), Devcon (ITW).