Dr Bhattacharyya has made valuable contribution, both applied and fundamental, in developing cutting tools technology for metal removal. His work has brought in new and original ideas in the design of cutting tools and several new types of cutting tools, such as (i) tangential-split modified point drill, (ii) retraced type Kolosov high production tools, and (iii) core drill with clamped inserts. Some of his noteworthy contributions are : (1) development of a new ceramic cutting tool material, tantalum nitrate-zirconium diboride, in collaboration with Carborundum Universal, Niagara Falls and Pennsylvania State University; (2) design and commercial development of an OPTOSCOPE for chip analysis in metal cutting research; (3) stochastic modelling of wear of cutting tools; (4) diffusion wear of cutting tools - the basic modelling; and (5) adhesion wear analysis at temperature sensitive regions.