The shear test method is recommended for shear testing of calcium phosphate and metallic/substrate combinations and can provide information on the adhesive or cohesive strength of coatings under a uniaxial shear stress.

The test method may be useful for comparative evaluation of adhesive or cohesive strengths of a variety of types of coatings. Information developed using this test method may be useful for certain quality control and design purposes.

The test method should not be considered to provide an intrinsic values for utilization directly in making calculations such as determining the ability of a coating to withstand specified environmental stresses.

Processing variables, such as substrate preparation prior to coating, surface texture, coating technique variables or post-coating heat treatment, or heat may introduce a significant effect on the results of the shear test. The specimen being evaluated must be representative of the actual end-use coating.