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. Although, the principle on which these 2 methods of testing impact resistance work is the same, still, they are different in many ways. Here, in this brief article, we are going to have a look at all the differences these methods have. But before we proceed to understand the difference between Izod and Charpy Impact Test, let’s first understand what these two testing methods are:
Izod Impact Test:
It is a standard testing method that is used to measure the impact resistance of a material. In this method, there is a hammer or striker which remains connected/fastened to a pendulum. During the test, the pendulum is released from a specific height. Once released, the striker swings/oscillates down, striking at the vertically-placed notched specimen (which is to be tested for its impact resistance) at its upper tip and causing it to get broken.
Charpy Impact Testing:
It is a standard testing method that is used to determine a material’s resistance against impact load with the use of a Charpy Tester. In this method, there is a hammer or striker which remains connected/fastened to a pendulum. During the test, the pendulum is released from a specific height. Once released, the striker swings/oscillates down, striking at the horizontally-placed notched specimen (which is to be tested for its impact resistance) at its center or middle point and causing it to get broken.
Note: You can read here in detail about the Charpy Test – What is it and what is involved in it?
Difference between Izod and Charpy Impact Test:
- Materials Tested:- By the Izod Test, both plastics and metals can be tested for their impact resistance. But the Charpy Test is useful in testing the impact resistance of metals only.
- Position of Test Material/Specimen:- The test material (specimen) is placed in a vertical position while testing the impact resistance of the material via the Izod Impact Test. And, in the Charpy Impact Test, the specimen is horizontally positioned.
- Notch-Type:- 2 Kinds of notches (V-Notch & U-Notch) are generally used when testing a material’s impact resistance. Any of these 2 types of notches can be used in Charpy Test whereas only V-Notch can be used when performing the Izod Impact Test for a material.
- Notch-Face Direction:- As far as the direction of the specimen’s notch is concerned, it faces the striker/hammer (which is connected to the pendulum) in the Izod Test. And, on the other hand, the notch-face is in the opposite direction or away from the hammer in the Charpy Test.
- Type of Striker/Hammer:- There is also a difference in the strikers or hammers used in both the Charpy and the Izod Tests. In the Charpy test, there is a Ball Pin Hammer whereas, in the case of the Izod Impact Test, a Farming Hammer is made use of.
- Size of Test Material/Specimen:- In the Izod Impact Test, the specimen’s size or dimension is usually 75mm x 10mm x 10mm. On the other hand, in the Charpy test, the size of the used specimen is 55mm x 10mm x 10mm.
- Striking Point:- In both the Izod Test and the Charpy Test, the striking point of the striker/hammer is different. In the case of the Izod Test, the striker strikes at the upper tip of the specimen. And, on the other hand, in the Charpy Impact Test, the striker/hammer strikes in the notch (at the center or middle point of the specimen).
We hope this brief article on the difference between Izod and Charpy Impact Test has helped you deeply understand the differences between these two testing methods. Still, in case there are any doubts/queries in your mind about the topic, you can leave a comment below.
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