Minerals and Metals in Ancient India v1.c11.s7.4

v1.c11.s7.4

In the case of blade-axes it is found that in comparison to bronze, copper has been used more. In such a case the axes were cast in open mould and then hammered to give them the requisite hardness. From Central Provinces a good number of copper implements have been found and there are ridges on the edges of several implements which suggest that these were cast in a closed mould. However copper is difficult to cast in this manner. There is a possibility that these implements corresponded to dates later than those of Mohenjo-Daro and a more advanced technique was employed in their manufacture. The absence of hammer-marks on all axes, suggest that these were carefully rubbed down after being hammered. Their straight cut sides and butts and only slightly rounded angles indicate some such treatment for these features, which were probably also present in the mould, but were destroyed in the process of hammering. The bronze blade-axes would have required very much the same treatment, though cleaner castings could be obtained with this alloy and therefore not so much hammering would be required to harden them. Their tin content served this latter purpose. (MS-II, 494)