What is a Hardness Tester?
A hardness tester sounds like something students use to select the courses they might want to avoid, but it is in fact a device for measuring the hardness of a material. Hardness is a characteristic of a given material defined as the resistance to indentation. We all have a conceptual definition of hardness, since we all understand when someone says that steel is harder than wood. A hardness tester allows the user to quantify this concept. Using a hardness tester, a person can say that material A is twice as hard as material B. There are over 12 different accepted methods of testing for hardness. The most common method is known as the Rockwell Hardness Tester, and the results are given in terms of the Rockwell hardness scale. A Rockwell Hardness Tester is used to measure the hardness of metals. There is a strictly defined method for preforming a Rockwell Hardness Test and specifically built Rockwell Hardness Testers. Metals are the most common materials for which a hardness tester is u
What’s its purpose on the shop floor? And what types of hardness testers are available? Hardness testers’ purpose “All hardness testers have the same thing in common,” explains Dick Ellis of David Ellis Co. “It’s a known load to a known penetrator. That’s it. That’s the whole story right there.” To elaborate, hardness testers are typically used to measure the resistance a piece of material will have against a set force. Often used to measure the hardness of heat-treated materials, including steel, they’re also used in testing plastics, rubber and other nonheat-treated substances. According to Ellis, around 50 percent of the hardness testers used today were built before the 1960s. “There were some new developments when the computer came out, but a hardness tester is just like a micrometer or an optical comparator–its basic principles stay the same,” says Ellis. “Think of it this way: A screwdriver works just fine; you don’t need to add a graphical display and lasers to it. It’s the sam
