It is well known that 7-3 Brass is used as Standard Block of Hardness. Recently it has been pointed out by many investigators, in consequence of the progress made in testing and extension of application field, that its hardness is not sufficient in homogeneity. The authors have studied on the improvement of homogeneity of the block by means of heat treatments and cold rolling, and by admixing foreign elements.
It has been found in the experimental results that the most effective factor for improvement of homogeneity is cold rolling, and the factor next in being effective is mixing additional elements. The most effective element to be added into is Be, and Al, Mn etc. to bellow it. However, Be is not reduced to low hardness but Al obtains low hardness by means of heat treatment Hardness loses in homogeneity by being annealed.
