Hardness Testing
The Test Methodology Guide, Part 3

Return to Part 2, or Part 1

Also see our recent article in ASM's Heat Treat Progress Magazine: Common Problems in Hardness Testing or Common Problems in Microhardness Testing

Section 3: How to Select a Hardness Tester

Fundamental to reliable hardness testing are several factors.

1. Choose the correct test method based on the application. Plan to use the highest test force and largest indenter possible. Consider the effects of the shape and dimensions of your test sample. Refer to Section 1

2. Many questions may need to be answered in order to determine the scale and tester to be used:

• Is there a hardness scale specified?
• What is the materials being tested and is it suitable for a a particular test?
• How large are the parts?
• Is the test point difficult to reach?
• What volume of testing is to be done?
• How accurate do the results need to be?
• What is the budget?
• What are the problems that have occurred in the past

3. Verify that the test results meet your needs for accuracy and repeatability. You may want to conduct a Gage R&R study to see how much error the operator and measurement system contribute.

There are significant differences between levels of performance within each classification of tester. A difficult job on one tester could be very simple and fast on another. So, although often hardness testers within a test method and classification look alike, there are many features that can significantly affect productivity and accuracy. A good example of features affecting performance is demonstrated in bench Rockwell hardness testing systems. All can handle moderately long parts using larger anvils or jack rests, however the Versitron can usually test large parts more quickly and accurately, when compared to other bench testers which require external support stands or fixtures. The Indentron, on the other hand, is much easier to use on small, awkward parts. If you need assistance with your application, contact a Newage Testing Instruments sales representative. Also the reader can follow this link for "Choosing the Right Hardness Tester"

TEST SPECIFICATIONS