Loctite instant universal low viscosity toughened gel amp flexible adhesives loctite 431 loctitereg 4318482 is designed for the assembly of difficult to bond materials which require uniform stress distribution and strong tension andor shear strength it provides rapid bonding of a wide range of materials including metals plastics and elastomers loctite 431 is also suited for bonding porous materials such as wood paper leather and fabric loctite 431 instant adhesive universa