Durometer

As a gauge that can be used to check the density or hardness of a given material, the durometer can be used in a number of different applications. Here is some information about durometers, and how the devices can be used in a variety of ways.

The durometer functions by analysing a given substance, and then assigning it a number to denote the level of harness and durability. A lower number would indicate a softer nature for the substance, while a higher number would indicate the product is harder and less susceptible to bending or cracking.

There are several scales of durometer, used for materials with different properties. The two most common scales, using slightly different measurement systems, are the ASTM D2240 type A and type D scales. The A scale is for softer plastics, while the D scale is for harder ones. However, the ASTM D2240-00 testing standard calls for a total of 12 scales, depending on the intended use; types A, B, C, D, DO, E, M, O, OO, OOO, OOO-S, and R. Each scale results in a value between 0 and 100, with higher values indicating a harder material.

Along with the number, there is also often a density rating, with lower density being indicated by an “A” and the higher density being rated as “D”. Thus, a substance that had an overall rating of A30 would be considered less dense and not very hard, compared to a substance with a reading of D70. Readings are generally based on checking several spots along the surface of the material and then making a cumulative rating based on the data.

While a durometer can technically be used to test the hardness of just about any substance, the main uses of the device are associated with measuring the hardness of rubber or plastic products. Generally, manufactures will have a range of hardness and density that they consider ideal for the type of goods they produce.

Using a durometer in the process of measuring hardness during the manufacturing process to ensure the mix of materials results in the type of density required can save a company a great deal of time and resources. Regular checks with durometer equipment will quickly identify any deviation from the standards employed by the company.

The results obtained from this test are a useful measure of relative resistance to indentation of various grades of polymers. However, the Shore Durometer hardness test does not serve well as a predictor of other properties such as strength or resistance to scratches, abrasion, or wear, and should not be used alone for product design specifications. Shore hardness is often used as a proxy for flexibility (flexural modulus) for the specification of elastometers. The correlation between Shore hardness and flexibility holds for similar materials, especially within a series of grades from the same product line, but this is an empirical and not a fundamental relationship.

At Techequip Australia we have a wide range of Portable Hardness Testers, with a range of products for general usage and a range of products that are for heavy duty industrial usage. We are a leading test equipment supplier in Australia.For more details on Durometer than please visit our website www.te2.com.au