ASTM D2240 Shore Hardness

ASTM D2240 test method is utilized to evaluate Durometer Hardness or Shore Hardness of polymeric and plastic materials. The Shore Hardness value is used as a quality control parameter for polymers, elastomers, plastics, and rubbers to be used in various applications.

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Overview
Scope, Applications, and Benefits
Test Process
Specifications
Instrumentation
Results and Deliverables

Overview

ASTM D2240, developed by ASTM International, outlines a procedure for determining the hardness of rubber, elastomers, and certain plastics using a durometer test instrument. The test for hardness involves measuring the resistance of the test material to indentation by a specified indenter under a specified spring force.

The test for hardness of flexible materials like rubber, thermoplastic elastomers, and soft plastics is commonly performed to help manufacturers determine the quality, uniformity, and acceptability of their products for various commercial and industrial purposes.

Scope, Applications, and Benefits

Scope

ASTM D2240 defines procedures for measuring hardness using Shore durometers across different material hardness ranges. The standard applies to materials that can be tested by indentation hardness methods.

The scope includes:

Measurement of hardness using Shore scales such as Shore A, Shore D, and others
Testing of rubber, elastomers, and soft to rigid plastics
Evaluation of hardness for quality control and material comparison
Testing of molded parts, sheets, and finished products
Procedures for hand-held or stand-mounted durometers

Applications

Rubber and elastomer product testing
Plastic and polymer material evaluation
Automotive seals, gaskets, and hoses
Consumer products such as footwear and protective equipment
Quality control in manufacturing industries

Benefits

Quick and simple hardness measurement method
Suitable for wide range of flexible materials
Provides consistent and repeatable hardness values
Helps ensure material compliance with specifications
Useful for product development and material comparison

Test Process

Specimen Preparation

Samples must have a flat, smooth surface with sufficient thickness for accurate hardness measurement.

Instrument Setup

The Shore durometer is calibrated, and the appropriate hardness scale is selected based on the material.

Hardness Measurement

The durometer indenter is pressed onto the specimen surface with controlled force.

Reading and Recording Results

The hardness value is read directly from the durometer scale and recorded as the Shore hardness value.

Technical Specifications

Parameter	Details
Measurement Type	Indentation hardness
Hardness Scales	Shore A, Shore D, Shore OO, Shore O, and others
Instrument	Shore Durometer
Indenter Type	Spring-loaded indenter
Specimen Requirement	Flat surface with sufficient thickness
Measurement Principle	Depth of indentation under standardized spring force

Instrumentation Used for Testing

Shore Durometer (Hardness Tester)
Durometer Test Stand for improved measurement accuracy
Calibration blocks for verification
Sample support platform

Results and Deliverables

Shore hardness value
Test report including test scale, conditions, and specimen details
Compliance evaluation according to ASTM D2240 requirements
Material hardness certification for quality assurance
Optional comparative analysis for different material batches

Why Choose Infinita Lab for Shore Hardness (

ASTM D2240)?

Infinita Lab is a trusted USA-based testing laboratory offeringShore Hardness (ASTM D2240) testing services across an extensive network of accredited facilities across the USA.

Infinita Lab is built to serve the full spectrum of modern testing needs—across industries, materials, and methodologies. Our advanced equipment and expert professionals deliver highly accurate and prompt test results, helping businesses achieve quality compliance and product reliability.

Looking for a trusted partner to achieve your research goals? Schedule a meeting with us, send us a request, or call us at (888) 878-3090 to learn more about our services and how we can support you. Request a Quote

Frequently Asked Questions

ASTM D2240 determines hardness by measuring the resistance of rubber, elastomers, and certain plastics to indentation using a durometer instrument, providing hardness values on specific Shore scales depending on material stiffness.

Common scales include Shore A for soft elastomers and rubber materials, and Shore D for harder plastics and rigid polymers, with other specialized scales used for very soft or extremely hard materials.

ASTM D2240 is widely used for testing rubber, thermoplastic elastomers, soft plastics, and other flexible polymer materials used in seals, gaskets, footwear, automotive components, and consumer products.

Shore hardness testing helps verify material consistency, ensure compliance with product specifications, and evaluate elasticity and stiffness, which are critical for product performance and durability.

Test results may be influenced by specimen thickness, surface smoothness, temperature conditions, and the specific durometer scale used during measurement.