Ames Testers represent Rockwell testing an old and reliable method for testing metal hardness. You can purchase are Standard and Superficial Ames tester models. Testers are designed to allow you to test in the field, and materials ranging from soft to hard metals. You might find yourself wondering “Which Hardness Test Works“? Compare the 5 major kinds of hardness tests and decide for yourself.
Top 3 hardness tests used in the metal industry today:
- Brinell: You have likely heard of this, the oldest method for testing metal hardness. You can easily convert Rockwell readings to Brinell. Download our Rockwell-Brinell conversion chart below!
- Ames Testers use the Rockwell Scale – You can see our full line of Rockwell hardness testers online!
- Vickers – Most commonly used in Europe and the UK. This is an extensive scale for hardness testing.
What is a Hardness Test?
In order to test the hardness of a metal, the test measures the metal’s resistance using a penetrator. A penetrator is non-deformable and is ball or cone-shaped. The hardness test determines the depth that the ball or cone sinks into the metal. Specific loads are used for each kind of hardness testing. As you can see in the picture above, the distance traveled by the penetrator is measured to calculate the hardness. When you use an Ames Hardness Tester, you will have a measurement in the Rockwell scale. Here are 5 of the most widely used hardness tests in metals:
1. Rockwell Hardness
Rockwell testing has become a standard in the hardness testing industry. This is a quick method that you can learn and apply with no preparation. Using a smaller penetrator than other tests, you can test very soft or very hard materials. This type of test is based on the net increase in depth of impression as a load is applied.
2. Brinell Hardness
Older than Rockwell, you can also use this test to measure soft and hard metals. It is limited to larger, flat pieces only. The indenter is quite large and leaves a noticeable mark. This test is determined by forcing a hard steel or carbide sphere of a specified diameter under a specified load into the surface of a material and measuring the diameter of the indentation that is left after the test.
3. Vickers Scale
This method was developed as an alternative to Brinell. It uses a smaller indentor and a load over the surface area of the indentation instead of applying pressure. You may find the Vickers Scale appealing because you can test anything from tin to ceramics. One of the difficulties is converting Vickers readings are quite loose and difficult to convert into Rockwell or Brinell.
4. Knoop
This scale was developed as an alternative to the Vickers technique. You might find it appealing as it was designed by the head of the National Bureau of Standards. You can use this method to test the thin materials that would crack with other testers. This method is used to test the relative micro-hardness of a material. It is most effective on small long test pieces.
5. Shore Testing
You will not want to use this scale for testing metals as it was designed to test hardness of plastics, polymers, and rubbers. This test measures hardness in terms of the elasticity of a material.
There is a lot to consider when you choose a hardness tester and a hardness scale. As you can see, each scale has an application just like this old conversion chart for Rockwell and Brinell scales. It still works but not if you are using the Shores method for hardness testing!