Shear Strength ASTM D3528

ASTM D3528 testing, used to determine tensile shear strengths of adhesives for bonded metals. The double lap shear configuration is an essentially peel free standard specimen, and used in this method to represent low-peel structural joints.

Intertek tests the strength properties of double lap shear adhesive joints by tension loading, using the ASTM D3528 test for measurement.

ASTM D3528 Test Procedure:

Metal plates are bonded together with adhesive in one of the configurations shown above and cured as specified. The assembly is then cut into uniform width double lap shear specimens. Cutting the test specimens from larger assemblies limits potential edge effects in the specimens. The test specimens are placed in the grips of a universal testing machine and pulled at 1.27 mm/min (0.05 in/min) until failure. The type of failure can be either adhesive (the adhesive separates from one of the substrates), cohesive (the adhesive ruptures within itself) or a break in one of the substrates.

Specimen size:

The recommended lap shear specimens are 25.4 mm (1”) wide, with an overlap of 12.7 mm (0.5”) at each of the bonds. The overall length of the bonded specimen should be 203 mm (8”) for Type A specimens and 218 mm (8.6”) for Type B specimens. Adhesive is applied per the manufacturer recommendation.

Data:

Load at Failure (N or lbf)
Shear Strength at Failure (MPa or PSI)
Type of failure (cohesive, adhesive, or substrate)