3M Polyurethane Sealant 540 is a gray, 310 mL cartridge adhesive specifically designed for sealing in construction, general industrial, and transportation industries. With a full cure time of 24 hours and a tack-free time of 1 hour, this polyurethane sealant offers a hardness of 40 Shore A and a tensile strength of 250 psi. Perfect for metal surfaces, it has a solids weight percent of approximately 90% and a modulus at 100% of 58 lb/in².