Master Tensile, Compression, and Flexural Testing on One Machine.

A key function of a universal testing machine is to perform tests in accordance with globally recognized standards to ensure that results are comparable and compliant. There are hundreds of such standards. For plastics, one of the most common tensile test standards is ASTM D638 or the very similar ISO 527. For metals, ASTM E8 is the fundamental standard for tensile testing. For compression testing of polymers, ASTM D695 is often used. Flexural properties are commonly tested using ASTM D790. These standards dictate everything from the shape and size of the test specimen to the speed of the test and how the results should be calculated. The software on a WBE universal testing machine comes with pre-configured modules for these and many other standards to simplify compliance.

Selecting the correct force capacity is the most critical decision when purchasing a universal testing machine. The capacity is the maximum force the machine can safely apply. To determine your required capacity, you must first identify all the materials you plan to test and find their estimated ultimate strengths. Your machine's capacity must be greater than the breaking force of your strongest material. However, it is also important not to oversize the machine excessively. The load cell, which measures the force, is most accurate in the middle of its range. If you are consistently testing very low-force samples on a very high-capacity machine, your accuracy may be compromised. In many cases, it is best to purchase a universal testing machine with a capacity for your strongest materials and then buy an additional, lower-range load cell that can be easily swapped in for more sensitive tests.

The main difference between a single-column and a dual-column universal testing machine lies in the construction of the load frame, which directly impacts its force capacity and rigidity. A single-column UTM, as its name implies, has a single vertical column supporting the moving crosshead. This design is more compact, making it ideal for benchtops and labs with limited space. It is typically used for lower-force applications (generally below 10 kN), such as testing films, textiles, plastics, elastomers, and medical devices. A dual-column UTM has two vertical support columns, creating a much more rigid frame. This increased rigidity is necessary to handle higher forces without the frame itself deflecting, which would compromise test accuracy. Dual-column machines are used for higher-force testing of materials like metals, composites, and construction components.

The universal testing machine is an indispensable tool for researchers and scientists working on the development of new materials. When a new polymer blend, metal alloy, or composite material is created, the UTM provides the first and most fundamental data on its mechanical performance. Researchers can quickly and easily create test specimens of the new material and use the UTM to measure its core properties: Is it stronger than the old material? Is it stiffer? Is it more brittle or more ductile? This rapid feedback allows for fast iteration, enabling scientists to tweak formulations and processing techniques to optimize the material's properties. Without the quantitative, reliable data provided by a universal testing machine, the process of developing new and innovative materials would be based on guesswork rather than science.