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Izod Impact Test

A test specimen, usually of squaare 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 wsings 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 by 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 dimesions laid down in BS 131.