Different Types of Material Hardness

In order to build or construct anything you need to know the hardness of the material you using in your construction process. Material hardness is the ability of a material to withstand force without deformation, scratching, penetration, or indentation. Why is this important to know before your production process begins or is in the early stages? Quite frankly, if you are going to pour money into producing something or constructing something, you want to make sure it can last through different scenarios that might happen and the limitations of the very thing your are producing. Materials behave differently under different conditions. That means knowing different types of material harnesses and how to test them. Let’s go over the different types of material hardness.

Different Types of Material Hardness

Scratch Hardness

Scratch hardness, simply put, is the ability of the material to resist scratches to its surface. Scratches happen When a sharp, more rigid material brushes through the surface of a softer material and causes narrow continuous lines. Scratch testing is generally used for brittle materials such as ceramics. It can also be used for parts that may require friction as a low scratch hardness may not be good enough.

A typical scratch hardness tester consists of a stylus, a movable sample holding stage, load-applying device, and a data processing and display unit. During a scratch hardness test, at a chosen constant load, the stylus is allowed to plow into the test specimen up to a predetermined distance to form a groove.

Rebound or Dynamic Hardness.

Rebound hardness “measures the height of the “bounce” of a diamond-tipped hammer dropped from a fixed height onto a material. One of devices used to take this measurement is known as a Scleroscope. It consists of a steel ball dropped from a fixed height. This type of hardness is related to elasticity” (Material-properties.org) Another way of testing rebound hardness is by dropping a diamond-tipped hammer on it and then measuring the hammer’s bound after striking the surface. If the hammer returns closer to the original dropping height, the material has a high value for rebound hardness. On the other hand, if the hammer didn’t get closer to the dropping height, the material has a low rebound hardness.

Indention Hardness

Indention hardness is the resistance of the material to deform upon the impact of a force. The way to measure this is using an impact hardness tester, or engineers and metallurgists may refer this as just hardness testers. The impact hardness is usually measured on a hardness scale, like Rockwell or Vickers, ones we have mentioned here often. Vickers is more suitable for soft materials that require lesser loads. Therefore, if you need better accuracy for your soft materials, the Vickers test is best for you. If you want to learn more about the different hardness scales used in indention hardness testing, read our piece called Comparing Hardness Scales.

To build anything of size or scale, you need to know the hardness of the materials you are working with. METSUCO has been in business for over 30 years selling metallurgical hardness testing equipment to many different industries including oil and gas, aerospace, automotive, heavy manufacturing, universities, and testing labs. Call 713-827-0700 or email sales@metsuco.com with inquiries.