BS ISO 4787 specifies a test method for determining the tensile lap shear strength of rigid-to-rigid bonded assemblies. This is one of the most common and fundamental tests for evaluating adhesive performance, particularly for structural applications where adhesives are used to join rigid components. The standard assesses the strength of an adhesive bond when subjected to a tensile force that induces shear stress in the adhesive layer within a lap joint configuration. The test involves bonding two rigid adherends with an overlap (lap joint) and then applying a tensile load along the axis of the joint until failure. The maximum load achieved before failure is used to calculate the lap shear strength, which represents the adhesive’s ability to resist forces that try to slide the joined components past each other. This value is critical for designing and selecting adhesives for applications requiring strong and reliable structural bonds, such as in automotive, aerospace, or construction.
