Commonly defined as the controlled heating and cooling of metals to change their microstructure and mechanical characteristics, such as hardness, ductility, tensile strength and impact resistance, heat treatment is a core phase in many manufacturing processes. It enables engineers to vary the properties of a given material to optimise its design performance and ensure consistent, reliable results. In this country, the top heat treatment technologies tend to be standard hardening, tempering, carburising, induction hardening and annealing processes, whereas in the States, where the industry is valued in excess of $20 billion, isothermal treatments like Austempering and, to a lesser extent, Martempering are much higher on the agenda. So are British design engineers and manufacturers losing out by not embracing these technologies?