ASTM D6110 defines the method used to determine the resistance of plastic to breakage when impacted in a three point bend configuration, using a pendulum system with an appropriately sized hammer arm. The test is typically uninstrumented and is used to determine the energy required to break the specimen. Different test parameters are specified according to the type of material that the specimen is made of as well as the type of notch cut in it. While similar to ISO 179-1 (Determination of Charpy Impact Properties–Non-Instrumented Impact Method) the defined tests are significantly different and therefore are not interchangeable.