World consumption at equal tensile stress million m X Youngs modulus

The average annual growth rate over the past 35 years is  

Expressed as Vickers hardness, the hardnesses of the engineering materials cover a vast range, broader than 1 to 100. The handful of example figures in Table 1.5 does not cover the hardnesses of rubbers, alveolar polymers and flexible thermoplastics. 

Year Plastics Polymer composites Aluminium Steel 

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