Shore (Durometer) hardness test

Dr. Dmitri Kopeliovich

Shore hardness is a measure of the resistance of a material to penetration of a spring loaded needle-like indenter.

Hardness of Polymers (rubbers, plastics) is usually measured by Shore scales.

Shore A scale is used for testing soft Elastomers (rubbers) and other soft polymers.
Hardness of hard elastomers and most other polymer materials (Thermoplastics, Thermosets) is measured by Shore D scale.

Shore hardness is tested with an instrument called Durometer.
Durometer utilizes an indenter loaded by a calibrated spring.
The measured hardness is determined by the penetration depth of the indenter under the load.

Two different indenter shapes (see the picture below) and two different spring loads are used for two Shore scales (A and D). The loading forces of Shore A: 1.812 lb (822 g), Shore D: 10 lb (4536 g).

Shore hardness value may vary in the range from 0 to 100. Maximum penetration for each scale is 0.097-0.1 inch (2.5-2.54 mm). This value corresponds to minimum Shore hardness: 0. Maximum hardness value 100 corresponds to zero penetration.

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• Polymer materials (Introduction)
• Polymer structure
• Glass transition
• Elastomers
• Thermoplastics
• Thermosets
• Tribology of polymers
• Methods of polymers fabrication
• Annealing of plastics
• Vulcanization of rubber
• Plastics welding
• Adhesives
• Paints
• Fluoropolymers
• Ion exchange resins
• Plastics recycling
• Combustion, pyrolysis and gasification of scrap tires
• Hardness test methods
• Hardness Conversion Table
• Hardness tests of ceramics

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