Definitions for "IZOD IMPACT TEST"
An impact strength test that gives a measure of toughness, the ability of a plastics material to resist breakage by flexural shock. The test samples are notched to create an area of greatest weakness. The notched specimen is then struck by a weighted pendulum and the results are expressed by a single number indicating the foot-pounds of energy required to break the specimen. Higher numbers therefore indicate greater impact strength. One of nine letters used to indicate different variations of the Rockwell Hardness Test, depending on the kind of penetrator used and the weight applied.
A test specimen, usually of square crossed section is notched and held between a pair of jaws, to be broken by a swinging or falling weight. When the pendulum of the Izod testing machine is released it swings with a downward movement and when it reaches the vertical the hammer makes contact with the specimen which is broken by the force of the blow. The hammer continues its upward motion but the energy absorbed in breaking the test piece reduces its momentum. A graduated scale enables a reading to be taken of the energy used to fracture the test piece. To obtain a representative result the average of three tests is used and to ensure that the results conform to those of the steel specification the test specimens should meet the standard dimensions laid down in BS 131. Contrast with Charpy test.
Test to determine impact strength of a sample by holding a sample bar at one end and broken by striking. Sample specimen can be either notched or unnotched.