This specification covers three types of urea-formaldehyde thermosetting resin adhesives suitable for use on wood, wood-based substrates, or plastic laminates. The requirements for the adhesive are based on tests of physical properties including viscosity, density, nonvolatile content, pH, insoluble matter, amylaceous matter, mixing properties, working life, and on strength properties, including dry shear strength in lumber-type joints, dry and wet shear strength in plywood-type joints, and all strength tests at the end of the storage life certified by the manufacturer. Testing procedures are specified to differentiate between the physical and adhesive bonding properties of the many commercial urea-formaldehyde thermosetting resin and catalyst systems. The adhesive bonding properties are measured on maple block and birch plywood specimens, prepared and tested in accordance with prescribed methods.