There are two methods of testing impact resistance (energy absorbed by a material when an impact load is applied) of a material. These two methods are Izod Impact Test and Charpy Impact Test. Both of these testing methods work on the same principle but still, they have many differences. In this article, we will discuss these differences. But before proceeding to know the difference between Izod and Charpy Impact Test, we should actually understand both of these testing methods briefly.
Izod Impact Testing:
Izod Impact Testing is a standard method of measuring the impact resistance of a material. In this, a striker or hammer attached to a pendulum is released from a height; which swings down and strikes at the upper tip and breaks the notched specimen (placed vertically) whose impact resistance is to be determined.
Charpy Impact Test:
Charpy Impact Testing is also a standard method of measuring the resistance of a material against sudden load or impact. In this, a striker or hammer attached to a pendulum is released from a height; which swings down and strikes at the center and breaks the notched specimen (placed horizontally) whose impact resistance is to be determined.
Difference between Izod and Charpy Impact Test:
- Position of Specimen/Test Material: – In the Izod Impact Test, the specimen is positioned vertically. On the other hand, it is positioned horizontally in the Charpy Impact Test.
- Direction of Notch-Face: – The notch of the test material faces the hammer/striker fastened to the pendulum in Izod Test. But, in case of Charpy Test, the face of the notch is away from the striker.
- Type of Notch: – In impact resistance testing, there two types of notches generally, V-Notch and U-Notch. In the Izod Impact Test, only V-Notch is used but in Charpy Impact Test V-Notch as well as U-Notch both can be used.
- Size of Specimen: – The dimension or size of the specimen used in the Izod Test is 75mm x 10mm x 10mm. On the other hand, the dimension of the specimen used is 55mm x 10mm x 10mm in Charpy Test.
- Type of Hammer: – The hammers used as a striker in both of the Izod and Charpy Impact Test are different from each other. In the Izod Test, Farming Hammer is used and in Charpy Test, Ball Pin Hammer is used as a striker.
- Striking Point: – The point at which the striker strikes or attacks during the experiment/test is also different in both of the tests. In the Izod Impact Test, the striker attacks or strikes at the upper tip of the test material/specimen. But in case of Charpy, it strikes at the middle point (in the notch) or center of the specimen.
- Material Tested: – Only metals can be tested by Charpy Test but Izod Test can be used for testing impact resistance of both metals and plastics.
I hope this article has furnished all the necessary information required to understand the difference between Izod and Charpy Impact Test.
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