Build Better Products with Reliable UTM Test Data.

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.

To ensure the ongoing accuracy and reliability of your universal testing machine, a regular schedule of calibration and maintenance is essential. Calibration is the process of verifying the machine's measurement systems (force, displacement, and strain) against a traceable reference standard. This is typically done annually by an accredited service technician and is crucial for maintaining quality certifications and data integrity. Maintenance involves routine checks and servicing of the machine's mechanical and electrical systems. This includes inspecting drive belts, lubricating lead screws, checking for worn grips, and ensuring all safety features are functioning correctly. A proactive approach to calibration and maintenance, like the service plans offered by WBE for our universal testing machine lineup, is the best way to protect your investment and ensure consistent, trustworthy test results.

The primary output of a tensile or compression test on a universal testing machine is the stress-strain curve, which is a graphical representation of the material's behavior. Stress (force per unit area) is plotted on the vertical axis, while Strain (percentage of deformation) is on the horizontal axis. The initial, linear portion of the curve shows the material's elastic behavior, and its slope is the Modulus of Elasticity, a measure of stiffness. The point where the curve begins to bend is the yield strength, where the material starts to deform permanently. The highest point on the curve is the ultimate tensile strength (UTS), the maximum stress the material can withstand. The final point on the curve is the fracture point, and the total strain at this point indicates the material's ductility. Understanding this curve is fundamental to materials engineering.