Loctite 431 prism medium viscosity, clear, gap filling, surface insensitive, one-part, room temperature cure, gap filling, surface insensitive instant adhesive. Designed for OEM assembly of difficult-to-bond materials which require uniform stress distribution. Particularly suited for bonding a wide range of materials, including metals, plastics and elastomers. - Loctite 431 is designed for the assembly of difficult to-bond materials which require uniform stress distribution and strong tension and/or shear strength. The product provides rapid bonding of a wide range of materials, including metals, plastics and elastomers.