ASTM International has established stringent tensile testing standards that manufacturers voluntarily follow to demonstrate their commitment to quality. Testing to the breaking load & elongation standards set by ASTM D412 is appropriate for many types of products related to resilient flooring, automotive materials, floor underlayments, tapes, and adhesives.
What is ASTM D412?
ASTM D412 is a standard that outlines procedures for breaking load & elongation testing of elastomeric materials — such as vulcanized rubber and thermoplastic elastomers — to determine tensile properties and how the material behaves under different loading conditions.
The evaluations check a given material’s elasticity and post-test capabilities after undergoing tensile strain. This rule outlines how a laboratory conducts tensile strength assessments on specimens.
- ASTM Method A uses specimens shaped like a dumbbell or dog bone at 3.0 +/- 0.3 mm thickness.
- ASTM Method B uses ring-shaped specimens for certain use cases.
To achieve ASTM certification under this testing guideline, the materials must meet or exceed behavioral standards that include elongation at break, tensile strength, and modulus.
How is the ASTM D412 Test Performed?
It’s essential that a testing facility invests in the specialized equipment needed to perform an accurate ASTM D412 examination. The equipment uses a controlled speed over a minimum distance of 750 mm. When conducted by an accredited firm, manufacturers gain a clear understanding of potential vulcanized rubber and thermoplastic elastomer applications based on the following.
- Tensile Strength: This metric involves the maximum stress used in stretching a material until it ruptures.
- Tensile Stress at a Given Elongation: This measures the strain needed to stretch a material to specific measurements.
- Ultimate Elongation: This identifies the greatest distance a specimen can be stretched before rupturing.
- Tensile Set: Once a specimen has been elongated, this metric assesses the remaining extension after it fully retracts.
Materials that meet ASTM specs have broad applications that go beyond automotive and household products. When they adhere to these stringent standards, the highest quality rubbers and thermoplastics are employed in the aerospace sector, among others.
Challenges Laboratories Face When Testing Specimens
It can be cost-intensive to maintain an in-house facility with the equipment, expertise, and technology to perform ASTM methods accurately. A third-party, independent test lab provides access to the necessary equipment and experienced professionals to conduct ASTM-certified testing that addresses and overcomes the following common challenges:
- Grip Specimens: As the materials are stretched, it’s not uncommon for subpar equipment to allow them to slip as they grow thinner. Industry-leading testing equipment is necessary to ensure a firm grip and accurate results.
- Elongated Specimens: Not every piece of equipment has the bandwidth to achieve the maximum elongation required under ATSM D412. Accurate testing calls for distances that result in rupture.
When selecting an ATSM testing organization, decision-makers would be well served to review the facility’s accreditations. Top-tier companies maintain Perry Johnson Laboratory Accreditation (PJLA), as well as the National Voluntary Laboratory Accreditation Program (NVLAP). Earning these accreditations ensures that ASTM D412 is rigorously administered using the latest tools, equipment, and technology by certified professionals.
The Professional Testing Laboratory Administers ASTM D412
At Professional Testing Laboratory, we earned PJLA and NVLAP accreditation to ensure our results exceed industry standards. We have more than three decades of experience and stringently follow ASTM guidelines. If you need an accredited facility to check these materials to ensure your final product is reliable, we conduct ASTM D412 testing. Contact us today to request a quote, and let’s get the process started.
