hardness testing Archives

There are distinct types of force tests that engineers, product designers, manufacturers, and test labs perform to accurately measure factors that control quality, safety, and reliability.

Testing force helps to qualify how something will react when applying load, either by a normal application or by pulling and pushing it fails. The type of force measurement classifications are compression, fracture, tension, flexure, and shear.

Interface provides a broad range of solutions for static and dynamic force measurement tests including standard and custom transducers, instrumentation, accessories, frames, calibration equipment and other components used for in force testing.

The most common categories of force testing include:

Tensile testing
Shear testing
Compression testing
Fatigue testing
Torque testing
Hardness testing
Static testing
Mechanical strength testing
Material testing
Proof load testing
End of line testing

There are variations to each of these test classifications, such as cycle testing is often a subset of fatigue and mechanical strength tests. Hardness testing is frequently referred to as nondestructive testing. Initial R&D tests typically center around choosing materials, strength and durability tests, compression ergonomic and abrasion tests.

Here are the general characterizations of the most popular types of force tests.

Tensile Test

Tensile strength is the ability of a metal to withstand a pulling apart tension stress. Performing a tensile test, sometimes referred to as tension testing, applies uniaxial load to a test bar and gradually increasing the load until it breaks. The measurement of the load is against the elongation using an extensometer. The tensile data is analyzed by using a stress-strain curve. Interface load cells are commonly used for various tensile tests when accuracy of measurement matters.

Compression Test

Compression is the result of forces pushing towards each other. The compression test is like the tensile test. Place the object in a testing machine, apply a load and record the deformation. A compressive stress-strain curve is drawn from the data. Interface provides load cells that measure compression-only or tension and compression measurements from the same device.

Torque Test

Torque measurement determines how an object will react when it is turned or twisted. There are two common use cases, fastening tests of objects or by testing rotating parts in an assembly. The two types of torque measurement are reaction and in-line, which are important when selecting the type of torque transducer to use in your test. The wrong torque can result in the assembly failing due to several problems, whether that is by torque testing bolts or engine parts. Parts may not be assembled securely enough for the unit to function properly, or threads may be stripped because the torque was too high, causing the unit to fail. Torque is a force producing rotation about an axis. This type of testing is also extremely popular in automotive to measure a variety of components.

Shear Test

Shear strength is the ability to resist a “sliding past” type of action when parallel, but slightly off-axis, forces, applied in the test. Shear force is directional force that is over the top of a surface or part. Shear is measured by tension or compression using a shear or bending beam load cell.

Hardness Test

Hardness testing, which measures the resistance of any material against penetration, is performed by creating an indentation on the surface of a material with a hard ball, a diamond pyramid or cone and then measuring the depth of penetration. Hardness testing is categorized as a non-destructive test since the indentation is small and may not affect the future usefulness of the material. There are a wide variety of hardness testing types as well.

Examples of Testing Types

Compression Test Example

Interface’s customer wanted to measure the amount of compression force a piece of candy could withstand to ensure its label is marked correctly. The purpose of the test was to correctly calibrate the equipment to provide the same stamping force each time without breaking the candy apart. An Interface Model WMC Mini Load Cell and 9330 Battery Powered High Speed Data Logging Indicator are used to measure the results. Read more about this compression test here.

Torque Measurement Example

In this example torque testing accurately measures the forced needed to securely fasten a bolt. This type of test is critical in highly regulated industries like aerospace and automotive to ensure every screw and bolt are not over or under-tightened. Interface’s LWCF Clamping Force Load Cell along with Interface’s INF-USB3 Universal Serial Bus Single Channel PC Interface Module provide a solution that monitors the force being applied during bolt tightening.

Shear Test Example

This example shows how aerospace manufactures use shear testing to measure the affects of wind as it moves past the wings, hull, and other components of a plane. Interface measured this force using a Model 6A154 6-Axis Load Cell mounted in the floor of the wind tunnel, and connected to the scaled model by a “stalk”. A BX8-AS Interface BlueDAQ Series Data Acquisition System was connected to the sensor to collect data.

As products become more complex and technologically advanced, the test and measurement industry must provide solutions to monitor a wide variety of factors. This is no different in force measurement.

Interface has been involved in every type of force measurement type across a variety of applications both large and small. To learn more about our more than 36,000 product SKUs designed to conduct all these tests, from single load cells and torque transducers to complete testing rigs and systems. We also provide calibration services for all types of force measurement transducers. Contact us if you are unsure which force measurement solution best fits your testing plan.

Additional Resources

Tensile Testing for 3D Materials

Material Tensile Testing

Interface Solutions for Material Testing Engineers

Bike Handlebar Fatigue Testing

Interface Specializes in Fatigue-Rated Load Cells

Specifying Accuracy Requirements When Selecting Load Cells

Spring Compression Testing App Note

Insights in Torque Testing Featured in Quality Magazine

Force measurement inherently is part of all types of engineering throughout the entire development process of products, structures, consumer goods, and the materials used to construct them.

In the beginning of the design and development processes, material testing engineers utilize sensor technologies and instrumentation to measure the durability, fatigue, safety, and quality of the materials used for their projects.

The role of a materials engineer is to develop, process, combine, and test materials to be used in production. Based on data gathered, combined with their expertise, the materials engineer will identify and recommend the appropriate materials for specific applications. Ultimately, they are the foundation of product development because it is their responsibility to select materials based on the use of the product, its ability to perform its task and function, and durability of materials to hold up over time. They also test for environmental impact and exposure considerations.

Five Categories of Material Testing

Mechanical testing
Testing for thermal properties
Testing for electrical properties
Testing for resistance to corrosion, radiation, and biological deterioration
Nondestructive testing (NDT)

Force measurement is most often used is in the material testing category of mechanical testing. This applies to testing materials used in all types of industries, including infrastructure, aerospace, automotive, industrial automation, manufacturing of consumer goods and in the machines used to assemble products. In mechanical testing, Interface sensors are commonly used to conduct:

Hardness Testing
Tensile Testing
Impact Testing
Fracture Toughness Testing
Creep Testing
Fatigue Testing
Nondestructive Testing

Interface Material Test Engineer Solutions

Material testing has been around since the first invention, to determine quality, durability and resilience of products and parts. What has changed over the centuries and decades is the sophistication of force testing and measurement. Interface’s robust line of load cells, torque transducers, multi-axis sensors, and instrumentation are used in about every industry for material testing. If it must be measured, Interface has a solution.

Interface’s force measurement products are being used to gather data from testing materials in applications used for industrial automation, structures, medical devices, vehicles on the ground and in the air, packaging, sports equipment and more. Material testing engineers ensure reliability and safety of the chosen materials. Here are examples of how material testing engineers use our products.

Tensile Testing of 3D Printing Materials

Interface was contacted by a test engineering team in search of a solution for conducting a tensile force test on different 3D printing materials until failure. They wanted to test several types of material types. The 3D printing materials to be tested to see how it performed included PLA, PETG and ASA. The test of the materials was to assess strength, quality, ductility, and stiffness. Interface supplied our most popular load cell, the 1200 Standard Precision LowProfile™ Load Cell, to install into the engineer’s test frame. The tensile test gathered the force results from the load cell that was synced through Interface’s instrumentation solution, the INF-USB3 Universal Serial Bus Single Channel PC Interface Module. The results were displayed on their computer with supplied software from Interface. Read more about this material testing application solution here.

Bike Frame Fatigue Testing

Fatigue testing is a critical material test used to ensure the materials used in a product hold up over time. A bike manufacturing company wanted to perform a fatigue test on their bike frames to analyze the strength of their frames, ensure durability and high-quality standards. Interface suggests installing Model 1000 Fatigue-Rated LowProfile™ Load Cell to the customer’s bike frame fatigue tester. This load cell will provide the customer highly accurate results through the fatigue cycling. Results are collected using the INF-USB3 Universal Serial Bus Single Channel PC Interface Module and displayed on the customer’s computer with Interface’s provided software. The bike manufacturing company successfully had their bikes undergo fatigue frame testing, receiving highly accurate results with Interface’s load cell and instrumentation. Watch the fatigue testing of the bike frame in this animated app note.

Spring Compression Testing

A customer wanted to evaluate the performance of their springs, but also the functionality of their spring test stand with a wireless solution. Interface suggested using one of their WTS-5200XYZ 3-Axis Force Moment Load Cell which has three integral WTSAM-1E Wireless Transmitters and installing it into the customer’s spring compression frame. The WTS-5200XYZ 3-Axis Force Moment Load Cell measured the force compression of the spring. The integral WTS-AM-1E Wireless Strain Bridge Transmitter Modules transmitted and displayed the information wirelessly to the LCCAXXX Wireless Instrument Enclosure. Using Interface’s solution, the customer was able to wirelessly get compression results on the spring being tested. They were also able to verify their spring compression test stand was working effectively.

Selecting the right material is critical to product develop and material testing engineers rely on Interface due to the accuracy and reliability of our solutions. If you have questions on what products are best suited for your material testing applications, please contact us.