Build Better Products with Reliable UTM Test Data.

A universal testing machine (UTM) is a foundational piece of equipment in materials science and quality control. Its primary job is to determine the mechanical properties of materials and components by applying a controlled force. The machine's powerful drive system moves a crosshead up or down at a precise speed. This movement applies a force to a specimen that is held in place by specialized grips or fixtures. A highly accurate sensor called a load cell measures the applied force, while an extensometer or the crosshead position measures the specimen's deformation or stretch. This data is plotted on a graph, typically a stress-strain curve, from which critical properties like strength, stiffness, and ductility are determined. Its "universal" capability allows it to perform various tests, such as pulling (tensile), pushing (compression), and bending (flexural).

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.

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.

The grips and fixtures are the critical interface between the universal testing machine and the specimen being tested. Using the correct type is essential for obtaining accurate results. The primary goal is to hold the specimen securely without causing it to slip or fail at the gripping point, which would invalidate the test. Grips, used for tensile tests, come in many forms, such as wedge grips for metals that tighten as force is applied, or pneumatic grips that provide constant pressure for softer materials. Fixtures are used for other tests; for example, compression platens must be large, flat, and parallel, while a three-point bend fixture must have precisely spaced, smooth supports. An investment in high-quality, appropriate grips and fixtures is just as important as the universal testing machine itself for ensuring data integrity.