ASTM D2000 Standard Classification System for Rubber Products in Automotive Applications

The system defined in the standard “ASTM D2000 Standard classification system for rubber products in automotive applications” developed by the American Society for Testing and Materials (ASTM) covers the properties of vulcanized rubber materials (natural rubber, recycled rubber, synthetic rubbers, alone or in combination) intended for use in rubber products for automotive applications, including, but not limited to,

This classification system can serve most needs in other industries, similar to Society of Automotive Engineers (SAE) steels. However, it should be noted that this system is subject to revision as automotive needs dictate. It is always recommended to use the latest revision.

This classification system is based on the assumption that the properties of all rubber products can be organized according to characteristic material definitions. These definitions are divided into types based on resistance to heat aging and classes based on resistance to oil swelling. This establishes basic levels that, along with values ​​defining additional requirements, allow for a complete description of the quality of all elastomeric materials.

In all cases where the provisions of this classification system conflict with the detailed specifications for a particular product, the latter shall take precedence.

If the rubber product is to be used for purposes where the requirements are so specific that they cannot be fully anticipated by this classification system, the purchaser should consult the supplier in advance to determine appropriate properties, test methods and property test limits.

ASTM D2000 is a widely recognized standard. Developed primarily by the Society of Automotive Engineers (SAE), it provides a comprehensive classification system for rubber products used in automotive applications. Its primary purpose is to simplify the specification and description of elastomer materials.

The purpose of this classification system is to guide engineers in selecting practical, commercially available rubber materials and to provide a method for identifying these materials using a simple line-calling notation. This classification system was developed to allow for the addition of descriptive values ​​for future rubber materials without requiring a complete redesign of the classification system and to facilitate the incorporation of future, state-of-the-art test methods to keep pace with changing industry requirements.

In this standard, each row classifying a product consists of different segments, each representing specific properties of the material. Each row contains seven different segments. For example, ASTM-D2000-99 M 2 ​​HK 7 14 A1-10, B38, C12, EF31, E088, F15, Z1.

• Specification revision: This refers to the D2000 revision year to which the line callout refers. For this example, the specification revision is ASTM-D2000-99. The "99" at the end of the standard number indicates the year in which this particular version of the standard was published or reapproved.
• Units of measurement definition: If an M is present in the line callout, it indicates that metric units will be used to measure tensile strength, temperature, and tear strength. If no M is present, English units are used. For the example, measurements are shown in metric units.
• Class number: The class is specified after the unit of measurement specification. This indicates the level of testing requirements to which a material can be subjected. Class 1 indicates that only basic properties are required, while Classes 2-9 require additional testing criteria, such as low-temperature embrittlement or special heat aging tests. In the example, the material must meet some or all of the requirements of Class 2. Class numbers do not apply to all material types and classes.
• Type and Grade: This is a key part of the ASTM D2000 designation and is designated by a single letter. The type represents the elastomer's tensile strength capabilities after heat aging for a fixed time at a specific temperature. The single letter following the type is called the grade. The grade represents the elastomer's resistance to swelling after immersion in ASTM oil for a fixed time at a specific temperature. The type and grade together indicate the polymer. In the example, the type and grade are "HK," which indicates fluoroelastomers. The most common polymers used for each type are listed in the table provided within the standard.
• Hardness or Durometer: This measures a material's resistance to permanent indentation or deformation. It's often used as a proxy for a material's overall flexibility or hardness. It's one of the key properties specified in ASTM D2000 line designations. Hardness is typically measured using the Shore A scale in the context of rubber or elastomeric products. A Shore A durometer is the most common device for measuring the hardness of elastomers, rubber, plastics, and non-metallic materials. For context, a rubber band might have a hardness of around 25 Shore A, a car tire might have a hardness of around 70, and a hard plastic skateboard wheel might have a hardness of around 98 Shore A. A material's hardness can affect its performance in applications, so understanding the Durometer number in this standard can help you choose the right material for your specific needs. For example, a harder material might better resist abrasion or deformation but also be less flexible. In the example, the number is "7," which indicates a hardness of 70 (plus/minus 5) in Shore A units. This means the material should have a hardness between 65 and 75 on the Shore A scale.
• Tensile strength: This immediately follows Durometer and is specified based on the unit of measurement. In the example, the material's tensile strength is 14 MPa. Tensile strength refers to the maximum amount of tensile (pulling) stress a material can withstand before failing or breaking. It's an important consideration for elastomers used in sealing applications because it can significantly impact their performance and durability under pressure. A higher tensile strength generally indicates a stronger, more durable material, while a lower tensile strength can indicate a softer, more flexible material. However, it's important to remember that tensile strength alone doesn't provide a complete picture of a material's performance or suitability for a particular application. It's just one of several properties, such as hardness, elongation, and resistance to specific environments, that should be considered when selecting a material for a specific application.
• Suffixes for additional requirements: Suffixes are combinations of letters and numbers that specify the testing and performance criteria for a material. Each letter-number pair corresponds to a specific requirement. In the example, these requirement suffixes are A1-10, B38, C12, EF31, E088, F15, and Z1. The suffixes indicate, respectively, a heat resistance test, compression set test, ozone resistance, fuel resistance, oil and lubricant resistance, low-temperature embrittlement criteria, and a special criterion that must be specified in detail.

In short, the ASTM D2000 standard provides a uniform classification system for describing the physical properties of rubber materials, making it easier for manufacturers, suppliers, and engineers to specify materials.

Our organization, which has been supporting businesses across all sectors for years through a wide range of testing, measurement, analysis, and evaluation activities, has a strong team of employees who closely follow global developments in science and technology and are constantly improving themselves. In this context, we also provide testing services in accordance with the ASTM D2000 Standard Classification System for Rubber Products in Automotive Applications.