ASTM D624 is one of the most important test standards for evaluating the tear resistance of vulcanized rubber and thermoplastic elastomers. For industries relying on elastomer components—such as packaging, medical devices, pharmaceuticals, electronics, and daily chemicals—understanding this method ensures accurate quality control and reliable material selection.
Tear failure is a common reason for service breakdown in rubber and elastomer products. When exposed to stress concentration, cuts, or defects, elastomers can gradually propagate tears, ultimately leading to material rupture. The rubber tear strength evaluation under ASTM D624 helps engineers understand how materials respond when subjected to tearing forces.
This measurement provides insights into:
Although test results do not directly equate to field performance, they form a critical foundation for comparative assessment and quality assurance.
The tear strength test of elastomers described in ASTM D624 involves applying a continuous tearing strain to a prepared specimen until complete rupture occurs. A tensile testing machine applies force at a controlled rate. The recorded maximum force, divided by the specimen thickness, represents the tear resistance.
Key factors influencing tear strength include:
Because each specimen design measures a different tearing behavior, ASTM D624 clearly states that results cannot be correlated between types. Choosing the correct geometry is essential for accurate evaluation.
ASTM D624 Type C uses a 90° angle specimen without a pre-cut notch. This type primarily measures tear initiation strength, focusing on how the material behaves at the point of stress concentration. If tearing fails to initiate at the apex, results can reflect tensile rather than tear behaviors.
ASTM D624 Type B employs a crescent-shaped, nicked specimen with gripping tabs. It provides reliable measurement of tear propagation, making it preferred when specimen size allows.
ASTM D624 Type A also evaluates tear propagation but is used when smaller sheet samples are available. Its geometry offers a compact alternative for limited materials.
ASTM D624 Type T follows the classic trouser tear design. The two legs are pulled apart while the machine records continuous force. This method clearly reflects propagation behavior along the leg length.
The ASTM D624 Type CP specimen is a refined version of the trouser tear design with a constrained tear path and thicker legs. This prevents deviations and reduces extension effects, providing more stable propagation data.
Accurate tear strength testing under ASTM D624 requires proper specimen preparation and precise instrument control. The typical steps include:
A stable, high-precision tensile tester is essential to ensure repeatability and minimize slippage or misalignment.
To help laboratories achieve accurate and repeatable results under the tear strength test standard ASTM D624, Cell Instruments offers the TST-01 Tensile Tester, designed for elastomer testing. Its precise control of test speeds, high-resolution force measurement, and customizable grips make it ideal for handling different ASTM D624 specimen types. The TST-01 supports flexible automation and tailored solutions for packaging, medical, rubber, and industrial material testing needs.
ASTM D624
Plastic
Rubber & Thermoplastic Elastomers
Standards