Information on the most widely used ASTM standards within the materials testing industry
Torsion Testing Machine
Torsion tests twist a material or test component to a specified degree, with a specified force, or until the material fails in torsion. The twisting force of a torsion test is applied to the test sample by anchoring one end so that it cannot move or rotate and applying a moment to the other end so that the sample is rotated about its axis. The rotating moment may also be applied to both ends of the sample but the ends must be rotated in opposite directions. The forces and mechanics found in this test are similar to those found in a piece of string that has one end held in a hand and the other end twisted by the other.
Material Torsion Testing Machine
Torsion tests twist a material or test component to a specified degree, with a specified force, or until the material fails in torsion. The twisting force of a torsion test is applied to the test sample by anchoring one end so that it cannot move or rotate and applying a moment to the other end so that the sample is rotated about its axis. The rotating moment may also be applied to both ends of the sample but the ends must be rotated in opposite directions. The forces and mechanics found in this test are similar to those found in a piece of string that has one end held in a hand and the other end twisted by the other.
Steel wire testing is the core means to evaluate the mechanical properties, toughness and surface quality of steel wires, and the core items include repeated torsion, repeated bending, winding tests, etc., to verify the reliability of steel wires by simulating actual use conditions, following international/domestic unified standards, and widely used in the whole industry chain of metal products.
High strength bolts are critical fasteners widely used in steel structures, aerospace, automotive, and heavy machinery industries, where they bear high tensile, shear, or combined loads. High strength bolts testing is a set of standardized procedures to verify their mechanical properties, reliability, and compliance with design requirements. The tests cover core performance indicators such as tensile strength, yield strength, hardness, torque-tension relationship, and fatigue resistance.
What's torsion testing?
The torsion test applies a rotational torque to a cylindrical or tubular specimen, measuring its torsional behavior under static or dynamic loading. It assesses key mechanical indicators including shear strength, torsional modulus of elasticity, yield torque, torsional ductility, and fracture toughness. Unlike tensile or compression tests, it focuses on a material’s performance under shear stress, revealing properties such as fatigue resistance and plastic deformation capacity under rotational forces. The test process involves gradually increasing torque until the specimen twists, yields, or fractures, while recording torque-twist angle data to generate characteristic curves.
Torsion tests twist a material or test component to a specified degree, with a specified force, or until the material fails in torsion. The twisting force of a torsion test is applied to the test sample by anchoring one end so that it cannot move or rotate and applying a moment to the other end so that the sample is rotated about its axis. The rotating moment may also be applied to both ends of the sample but the ends must be rotated in opposite directions. The forces and mechanics found in this test are similar to those found in a piece of string that has one end held in a hand and the other end twisted by the other.
Purpose of torsion testing
The purpose of a torsion test is to determine the behavior a material or test sample exhibits when twisted or under torsional forces as a result of applied moments that cause shear stress about the axis. Measurable values include: the modulus of elasticity in shear, yield shear strength, torsional fatigue life, ductility, ultimate shear strength, and modulus of rupture in shear. These values are similar but not the same as those measured by a tensile test and are important in manufacturing as they may be used to simulate the service conditions, check the product’s quality and design, and ensure that it was manufactured correctly.
Types of materials and standards
Many materials experience torques or torsional forces in their applications and so will benefit from or require torsion testing. Materials used in structural, biomedical and automotive applications are among the more common materials to experience torsion in their applications. These materials may be composed of metals, plastics, woods, polymers, composites, or ceramics among others and commonly take the forms of fasteners, rods, beams, tubes and wires.
International Standards:
ISO 7800: Specifies static torsion testing methods for metallic materials.
ISO 1397: Covers torsion testing of tubes for pressure purposes.
ASTM E143: Standard test method for torsion testing of metallic materials.
Material-Specific Standards: Separate standards exist for non-metals (e.g., plastics, composites) and components (e.g., fasteners, shafts) to adapt to their unique properties.
Types of torsion tests:
The three common forms that torsion testing take include failure, proof and operational. A torsion test for failure requires that the test sample be twisted until it breaks and is designed to measure the strength of the sample. A proof test is designed to observe the material under a specified torque load over a set period of time.
Finally, operational testing is measures the material’s performance under the expected service conditions of its application. All of these forms of tests may be performed with either torsion only loading or a combination of torsion and axial (tension or compression) loading depending upon the characteristics to be measured.
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