4.1 Column crush tests only provide information about the crush properties of blown thermoplastic containers when employed under conditions approximating those under which the tests are conducted.

4.2 The column crush properties include the crushing yield load, deflection at crushing yield load, crushing load at failure, and apparent crushing stiffness. Blown thermoplastic containers made from materials that possess a low order of ductility can fail in crushing by brittle fracture. In such cases, the crushing yield load is equivalent to the crushing load at failure. Blown thermoplastic containers made of ductile materials do not always exhibit a crushing load at failure although they will normally provide a crushing yield load value.

4.3 Column crush tests provide a standard method of obtaining data for research and development, applications, design, quality control, acceptance or rejection under specifications, and special purposes. The tests cannot be considered significant for engineering design in applications differing widely from the load - time scale of the standard test. Such applications require additional tests such as impact, creep, and fatigue.