What Is ASTM D412?
ASTM D412 is a standard needed to test the tensile (tension) properties of vulcanized thermoset rubbers and thermoplastic elastomers.
This process involves five main steps: Test material selection and preparation, specimen installation, extensometer attachment, testing, and data analysis. Test materials should be carefully considered for the specific application of use so that data collected is relevant to the desired end product requirements. Specimens must then be prepared following the ASTM protocol guidelines in order to ensure accuracy of results. To actually measure material’s performance or behavior under stress or strain during the test itself, careful consideration must be given to the testing methodology employed. Use of an extensometer although optional, gives the user more information and data. Finally, after all measurements have been taken and recorded, they must be properly analyzed to obtain key characteristics such as hardness, tensile strength according to ASTM D412 standards.
ASTM D412 Step By Step
- Cut your testing sample into a dumbbell Shape, as per image
- Place the sample in the tensile grips
- Attach the extensometer to the sample (optional)
- Start the test at a speed of 20 inch per minute
- Stop the test after sample break and analyze the data
Test Analysis obtained:
- Stress at user-specified extension or elongation
- Tensile Yield Stress
- Tensile Yield Strain
- Tensile Strength at Rupture
- Elongation at Rupture
ASTM D412 Test Machines:
Universal testing machine (tensile testing machine) with these minimum specifications:
A. Servo-controlled to keep a constant rate of speed during the test (+/- 2 inches/min)
B. At least 30 inches of crosshead travel or more for high elongation materials
C. Most small and common 1kN (225 pound) load capacity machines will work for the loads of the materials tested to this specification.
Frank Bacon has many available test options:
- 450LBF (2KN) INSTRON 4464 ASTM D412 TEST SYSTEM available for sale
- Instron 1011
- NEW FB-5EMS-TT
Test Fixtures available:
- Pneumatic Grips or Roller Grips
- Long Travel Extensometer
- Material Testing Software