History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c13.s4.6

v1.c13.s4.6

There is ample evidence that during the period of Indus Valley civilization Indian craftsmen had gained high level of knowledge regarding the effect of cold working of metals and their recovery on annealing and perhaps they also knew the improvements achieved by hot working of metals. Following is a short account of some of the metal forming technology and the skill achieved by the ancient Indians in improving the properties by thermal treatments such as annealing, hardening and tempering of metals.