The effect of polymer blends, viz. NR/BR, NR/SBR and SBR/BR, and cure parameters such as cure time and cure temperature on the hardness of a tyre tread compound has been investigated. Along with the hardness, other physical properties have also been measured with variation of the above blend compositions and cure parameters. The empirical relationships of the hardness with weight fraction of individual component of the blends, cure time and cure temperature have been established.