When you operate a portable hardness tester, such as the King hardness tester, it is because you want to know something valuable about the material or object you are testing. Portable testers, or field testers, also help you to conduct hardness tests outside the lab. These testers are a convenient way of gathering data without having to take the object or sample back to the lab. In the case of thread gauges, there are a few reasons why you would want to test their hardness.
1. Durability of the Thread Gauge
Some of the jobs thread gauges are expected to do require them to be extremely durable. You would not want a thread gauge that cannot withstand "x" amount of PSI (pressure per square inch) installed in a position where the PSI is above what the thread gauge can handle. Usually, the gauge itself comes with information that will tell you how much pressure it can handle, but that is not always the case. Additionally, if you wanted to know how much pressure an old thread gauge could handle, that information is long gone after years of sitting around, or in its current installed position.
2. The Strength of the Threads
Every once in a while, you buy a cheap thread gauge and the threads break off and crumble like cardboard. That is unfortunate as the manufacturer should have put the gauge through hardness testing on the threads before sending it to market. On the flip side, if you work in research and development, you can use a hardness tester to test the strength of the threads before moving forward with production. It helps to know that your company is selling a quality product with strong screw threads.
3. The Tolerance Level of the Shafts of the Gauges
Some thread gauges have thin body shafts, while others have thick ones. They are made from all types of materials, from titanium to plastic. The shafts of these gauges are just as important as the ends themselves. They have to have a uniform tolerance level. Hardness testers look for the weak points in the gauges. There is an acceptable level of weakness, and everything after that is, of course, unacceptable. Manufacturers of thread gauges check multiple gauges as they come off the production line to make sure each batch of gauges falls within the acceptable range of weakness and/or number of weak points before it passes inspection and can be sold.