What Is Mechanical Testing: Different Types of Mechanical Testing of Materials Mechanical testing is a series of tests used in product design and part manufacturing for material identification, characterization, selection, and validation of products. As a result, manufacturers can ensure proper material utilization, safety during production, and cost-effectiveness. This article will introduce the series of tests and their applications in product design and part manufacturing.     What is Mechanical Testing? Mechanical testing is a series of standardized tests used to determine a material’s physical and mechanical properties and suitability for its proposed applications. It is a huge requirement in product design and part manufacturing due to the need to achieve standards set by organizations such as ASTM and ISO. These tests allow manufacturers to distinguish materials of less quality and choose the right material for their products.  Tensile Testing Tensile testing is a fundamental mechanical strength test used to determine material properties such as stress, strain, and yield deformation. It involves subjecting a material to a force on opposite ends and pulling till it breaks. Testing occurs in a tensile testing machine that is either hydraulic or electric. The operator subjects the material to different forces and records the data. Afterward, they plot the data to get the stress-strain curve in a graph. Common standards for the tensile test include ASTM D638 / ISO 527-2 (for reinforced plastics), ASTM D412 / ISO 37 (vulcanized rubber and thermoplastic elastomers), and ASTM E8 / ASTM A370 / ISO 6892 (metals and other metallic materials).   Torsion Testing   Torsion testing is another form of mechanical testing that evaluates a material’s behavior when subjected to stress at an angular displacement. As a result, it gives information about the material’s shear modulus of elasticity, shear yield strength, shear strength, shear modulus of rupture, and ductility. In contrast to tensile testing, torsion testing applies to materials and products. Furthermore, there are several types explained below. Torsion only: Applying only torsional load to the material Axial-torsion Applying axial (tension/compression) and torsional force to a material. Failure testing: Twisting the product or material until it breaks or there is a visible defect. Proof testing Applying a torsional load to the material and holding the torque for a certain time. Functional testing: Final testing to verify a material’s behavior under torsional forces and loads.   According to ASTM and ISO, common standards for torsional testing are ASTM A938/ ISO 7800 (Torsion Testing of Metallic Wire). Fatigue Testing   Fatigue mechanical testing determines how a material behaves under fluctuating loads applied axially, in torsion, or flexure. It involves subjecting the material to a mean load and an alternating load. As a result, the material will experience fatigue (i.e., when the material breaks). The data will be presented from the test in an S-N diagram – a plot of the number of cycles to cause failure against the amplitude of cyclical stress (which can be stress amplitude, max stress, or min stress). Fracture Mechanics Testing   Fracture mechanics testing allows manufacturers to determine the energy it will take to break material with an existing crack into two. Furthermore, it allows the manufacturer to ascertain the material’s ability resist fracturing using the intrinsic stress factor. From the data, manufacturers can analyze the brittle fracture and examine its grain size, case depth, etc. Common standards for the test are BS 7448, NS-EN 10225, ASTM E1820, and EEMUA pub. 158. Compressive Testing Compressive testing is another fundamental mechanical engineering test determining the material’s behavior when subjected to crushing loads. As a  result, it is very important in part manufacturing because materials pass through different phases. It is suitable for a wide variety of testing materials such as metals, plastics, ceramics, or other users in load-bearing capacity. Common standards for compressive testing are ASTM D3574 (flexible cellular materials) ASTM D695-15 (Rigid Plastics), AITM 0010, ASTM C109 (2-Inch Concrete Cubes), ISO 844 (Rigid Cellular Plastics). Creep Testing   Creep testing or stress-relaxation test involves subjecting the material to constant stress at high temperatures and recording the deformation at a specific time interval. Afterward, operators plot the creep against the time on a graph to get the creep rate (slope of the graph). This test allows manufacturers to determine a material’s tendency to deform under constant stress at constant temperatures (to incorporate thermal expansion or shrinkage). It is important for materials such as metal workings, springs, and soldered joints.