Shore Hardness ASTM D2240
Durometer Hardness, also known as Shore Hardness, is a widely used test method for measuring the hardness of soft materials, especially rubber and plastic. This test is essential in determining the quality and consistency of materials used in various industries such as automotive, aerospace, construction, and medical devices.
The ASTM D2240 standard outlines the test procedure for measuring the hardness of elastomers using a durometer. The test involves measuring the depth of penetration of a specific indentor into the material under specific conditions of force and time. The result is expressed as a hardness value on a scale ranging from 0 to 100, with higher values indicating harder materials.
To perform the test, the specimen is first placed on a hard, flat surface. Then, the indentor, which is made of steel or carbide, is pressed into the specimen while ensuring that it is parallel to the surface. The reading is taken within one second of firm contact with the specimen or as specified by the customer.
The size of the specimen used for the test is generally 6.4mm (¼ in) thick. It is possible to stack several specimens to achieve this thickness, but one specimen is preferred for accuracy.
The durometer hardness test results are reported in either Shore A or Shore D scales, depending on the type of material being tested. The Shore A scale is used for softer materials, while the Shore D scale is used for harder materials. The Shore A scale ranges from 0 to 100, with 0 being the softest and 100 being the hardest. The Shore D scale ranges from 0 to 100, with 0 being the softest and 100 being the hardest.
In summary, the durometer hardness test is a crucial method for measuring the hardness of soft materials such as rubber and plastic. It is widely used in various industries to ensure the quality and consistency of materials. The test involves pressing an indentor into a specimen, and the results are reported on a scale ranging from 0 to 100, with higher values indicating harder materials.