The intent of this method is to provide a means of measuring the ultimate shear strength of aluminum-alloy wrought and cast products. Data obtained by this method are used to calculate minimum properties that can be utilized in the design of structural members such as found in aircraft. It is recognized that loading conditions developed by this method, and by most others, are not ideal in that they do not strictly satisfy the definition of pure shear. However, rarely do pure shear conditions exist in structures.

Note 2-This method is not interchangeable with that described in Test Method B 565. Shear strengths obtained by Test Method B 565 are about 10 % lower than those developed by this test method.

The presence of a lubricant on the surface of the specimen and fixture may result in shear strengths up to 3 % lower than those determined in the absence of lubrication (see 8.1 and Test Method B 565).