Hardness Test Analytical Service

Service Overview

Hardness is the ability of a material to resist indentation by a harder object. It can also be described as the resistance to localized deformation, especially plastic deformation, indentation, or scratching. Hardness is one of the essential properties of a material and is inherently related to other strength and plasticity indicators. Hardness values (e.g., Brinell Hardness, HBS) can indirectly reflect the strength of metals and variations in their chemical composition, microstructure, and heat treatment processes.

Generally, the harder a material, the better its wear resistance. In mechanical manufacturing, tools, gauges, molds, and other components require sufficient hardness to ensure performance and longevity. Some mechanical parts, such as gears, also need a certain hardness level to guarantee durability and service life.

Hardness testing is straightforward and rapid, allowing measurements directly on raw materials or part surfaces, making it widely applicable.

The most commonly used hardness testing methods are indentation tests, primarily including Brinell Hardness (HB), Rockwell Hardness (HR), and Vickers Hardness (HV).

1. Brinell Hardness (HB)

• Principle: A quenched steel ball or carbide ball of diameter $D$ is pressed into the sample's surface with a specified force for a set time. The ball leaves a spherical indentation, and the Brinell Hardness value is calculated as the average pressure applied over the unit area of the indentation.

• Interpretation:

  • Softer materials produce larger indentation diameters, resulting in lower Brinell Hardness values.
  • Harder materials yield smaller indentation diameters and higher Brinell Hardness values.
  • Brinell Hardness is commonly represented as HB, or HBW for values between 450 and 650 where a carbide ball is used

2. Rockwell Hardness (HR)

• Principle: A hardened steel ball (diameter 1.588 mm) or a diamond cone with a 120° apex is pressed into the sample's surface. The hardness value is determined by the depth of the indentation left after applying the load, represented as HR.

• Interpretation:

  • Shallower indentations correspond to higher Rockwell Hardness values.
  • Deeper indentations indicate lower values.
  • Rockwell Hardness has three common scales (HRA, HRB, and HRC), with HRC being the most widely used.

• Advantages:

  • Quick and simple operation, with direct readings from the dial.
  • Can measure the hardness of thin workpieces due to low applied pressure.

• Disadvantages:

  • Lower precision and greater variation in hardness values. Multiple measurements across different sample locations are required to average the material's hardness.

3. Vickers Hardness (HV)

• Principle: Vickers testing is similar to Brinell testing but uses a diamond pyramid-shaped indenter with a 136° apex. Under a specific load, the indenter creates a square-shaped indentation on the sample's surface. The hardness value is calculated based on the pressure over the unit area of the indentation, and the diagonal lengths are measured under a microscope to determine the hardness.

• Interpretation:

  • Vickers Hardness testing can measure materials ranging from extremely soft to very hard using a single scale.
  • Since the applied load is small, it is ideal for testing surface layers (e.g., hardened layers, coatings, or thin metal sheets) with high accuracy.

• Advantages:

  • Can measure a wide range of materials, from very soft to very hard.
  • Accurate and suitable for thin films and coatings.

• Disadvantages:

  • Requires measurement of indentation diagonals, making the process slower and more complex than Rockwell Hardness testing.

4. Shore Hardness (HS)

• Principle: A Shore hardness tester is used to measure materials like rubber and soft plastics. A spring-connected needle is inserted into the material's surface, and the needle's depth of penetration determines the hardness value displayed on the dial.

* The price on our website is for reference only. 

* Note: Data analysis service is not included in the list prices.

Highlights: High Quality Data, Competitive Pricing, Technical Support by Scientists.

Analytical Service Minimum order requirement: $250 per order. A $200 handling fee will be applied if order is below $250.

Please contact sales@msesupplies.com for additional information and instructions on our Analytical Services program. Confirmation of the sample(s) requirements, SDS sheets and additional information is needed prior to processing the Analytical Service order. 

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