What is the ASTM tensile test standard for rubber?

ASTM D412 measures the elasticity of a material while under tensile strength, as well as its behavior after testing when the material is no longer being stressed. ASTM D412 is conducted on a universal testing machine (also called a tensile testing machine) at a rate of 500  mm/min until the specimen fails.  Tensile testing for rubber involves measuring the material's resistance to stretching and its ability to elongate before failure. This test is crucial for determining the mechanical properties of rubber materials, such as tensile strength and elongation at break.

ASTM D412 is a standard for tensile testing of vulcanized rubber and thermoplastic elastomers, covering the measurement of a variety of tensile properties, including tensile strength, yield point, ultimate elongation, etc. The following is a detailed introduction to ASTM D412:

ASTM D412 Standard Overview
Standard Definition:

ASTM D412 is a standard issued by the American Society for Testing and Materials (ASTM) for determining the tensile properties of vulcanized (thermosetting) rubber and thermoplastic elastomers.
Test Method: ASTM D412 covers two test methods, Method A and Method B, which are applicable to different specimen types.
Application Areas: This standard is widely used in consumer products such as tires, footballs, rubber bands, and highly specialized materials such as O-rings on space shuttles.
Test Method
Method A: Applicable to dog bones and strip specimens, measuring tensile stress, yield point and tensile strength.
Method B: Applicable to ring specimens, performing stress calculations and multiple test case analysis.
Test Equipment and Materials
High and Low Temperature Universal Tensile Testing Machine: Used to simulate the expected final application conditions.
Non-contact video extensometer: used for strain measurement, avoiding the slipping problem of contact extensometer.
Pneumatic side-actuated clamps or self-tightening eccentric clamps: ensure that the specimen maintains a stable clamping force during the test.
Micrometer: used for accurate measurement of the specimen.
Test steps
1. Specimen preparation: select the appropriate specimen and cut it according to the specimen type.
2. Specimen measurement: use a micrometer to measure the size of the specimen.
3. Specimen alignment: ensure that the specimen is perpendicular to the clamp surface.
4. Operation steps: install the specimen, set the test machine parameters, start the test, and record the data.
Test result analysis
Tensile strength: the maximum tensile stress used to stretch the specimen to break.
Tensile stress at a given elongation: the stress required to stretch the equal cross-section of the specimen to a given elongation.
Ultimate elongation: the elongation at which rupture occurs during continuous application of tensile stress.
Through the above information, you can fully understand the ASTM D412 standard and its application in the tensile properties test of vulcanized rubber and thermoplastic elastomers.