How to Perform a Shear Test to ISO 4587

Written by Meredith Bernstein

This standard is used to test the shear strength of cured bonds when adhesives are applied to materials such as metals, plastics, wood, or composites. This is a critical characteristic of any adhesive, as they can exhibit unique shear properties. Manufacturers use this test method to investigate the shear properties of bonded rigid assemblies where the force applied is parallel to the bonded area and the length of the specimen. Stress is applied to the specimens at a rate of 8.3 to 9.8 MPa per minute and the breaking load and shear strength are reported.

Testing to ISO 4587 requires a universal testing machine. System capacity will depend on the strength of the adhesive, however most tests to this standard will fall in the capacity range between 1 kN and 5 kN, appropriate for a frame such as Instron's 34SC or 68SC. If the adhesive requires a higher capacity system, Instron’s dual column table model frames are available up to 50 kN.

Pneumatic side action grips and advanced side action grips are optimal choices for testing to ISO 4587. Both types of grips are adjustable in order to offset the jaw faces and ensure that the lap joint remains centered in the grips. They both feature quick-change jaw faces that can be easily changed to accommodate different materials.

•  ISO 4587 is performed on rigid specimens bonded via a lap joint, which causes the two ends of the specimen to be offset from the vertical load line of the test. It is critical that the gripping solution account for this overlap with offset jaw faces in order to ensure a true shear force application.

• The standard requires reporting the breaking force or strength, however, it is important to remember that the shear strength is calculated by dividing the breaking force by the adhesive bond area.