ASTM D2240

Welcome to our ASTM D2240 testing services page for evaluating “Shore hardness” as part of our analysis of plastics and polymers. This standard, ASTM D2240, also known as “Rubber Property—Durometer Hardness,” allows for the measurement of a material’s hardness by indenting the material with a standardized tip under a defined force. The depth of indentation is proportional to the Shore hardness and ductility of the material as well as the geometry of the indentation tip used.

Utility and Advantages of ASTM D2240

ASTM D2240 allows for the measurement of initial hardness or indentation hardness after a given time. The test involves applying a constant force without impact and then measuring the hardness. A total of twelve hardness scales are used without a mathematical link between increments; they are simply arbitrary. However, it is important to determine the appropriate scale based on the laboratory.

This test offers several significant advantages, including:

• Precise evaluation of material durability and strength.
• Assistance in selecting the optimal material for your specific needs.
• Compliance with international standards, ensuring global recognition of your products’ quality.

Materials Testable to ASTM D2240

The ASTM D2240 test is used to measure the hardness of various materials, mainly elastomers, plastics and other polymers. This standard ensures that they meet the hardness specifications required for their intended application, which is crucial for performance, safety and customer satisfaction. Here is a list of materials commonly tested using ASTM D2240:

Here is a list of materials commonly tested using this standard:

• Natural and synthetic rubber: Shore hardness testing is often used to test the hardness of rubber, whether used in tires, seals, hoses or other rubber products.
• Thermoplastic elastomers (TPEs): Combining the properties of rubber with the ease of thermoplastics processing, these elastomers can also be evaluated for hardness using ASTM D2240.
• Plastics: Some softer plastics can be tested using the Shore A scale, while harder plastics are often evaluated using the Shore D scale.
• Silicones and silicone gels: Used in a variety of medical and industrial applications, silicone-based materials are tested for hardness to ensure that they meet the specifications required for their intended use.
• Polyurethanes: Polyurethanes can vary considerably in hardness, from very soft materials to very hard plastics, and are therefore rated on different Shore scales according to their hardness.
• Vinyl: Flexible vinyl used in flooring, clothing and other applications can be tested for hardness and durability.
• Nitrile rubber, EPDM (ethylene propylene diene monomer) and other specialty rubbers: These materials are evaluated for hardness to determine their suitability for specific applications, such as chemical-resistant gaskets and hoses.
• Foams and foams: Foams used in packaging applications, seating and other areas are also tested for hardness to assess their ability to absorb shock and hold their shape.

ASTM D2240 Parameters and Implementation for Accurate Testing

• Initial hardness or timed hardness? (Initial hardness is most common)
• Sample geometry: Flat and homogeneous (without texture)
• Durometer scale to use: The most commonly used durometer scales are “A” and “B.” These two scales combined cover the hardnesses of rubbers to nylons.
• Number of samples or products: 1 sample, 5 measurements
• Sample size: 2″ X 2″ or larger with a minimum thickness of 0.64 mm (0.025 in.)
• Conditioning and testing temperature: 23 ± 2°C
• Conditioning and testing humidity: 50 ± 5%