Shore durometer °Sh or >90 °Sh the results are not to be trusted. The measurement must be redone with adjacent scale type. Durometer is a dimensionless quantity, and there is no simple relationship between a material's durometer in one scale, and its durometer in any other scale, or by any other hardness test. Using linear elastic indentation hardness, a relation between the ASTM D2240 hardness and the Young's modulus for elastomers has been derived by Gent and by Mix and Alan Jeffrey Giacomin. Gent's relation has the form where formula_2 is the Young's modulus in MPa and formula_3 is the ASTM D2240
Materials science Polymers are the raw materials (the resins) used to make what are commonly called plastics and rubber. Plastics and rubber are really the final product, created after one or more polymers or additives have been added to a resin during processing, which is then shaped into a final form. Plastics which have been around, and which are in current widespread use, include polyethylene, polypropylene, polyvinyl chloride (PVC), polystyrene, nylons, polyesters, acrylics, polyurethanes, and polycarbonates and also rubbers which have been around are natural rubber, styrene-butadiene rubber, chloroprene, and butadiene rubber. Plastics are generally classified as "commodity", "specialty" and "engineering" plastics.