Alongside silversmithing, Mellor was stimulated by the relatively new design potential of
stainless steel. His "Symbol" cutlery, manufactured from 1963 at Walker & Hall's purpose-built modern factory at
Bolsover in
Derbyshire, was the first high-quality stainless-steel cutlery to be produced in quantity in the UK. Mellor was subsequently commissioned by the government to redesign standard issue cutlery for canteens, hospitals, prisons and the railways, reducing the traditional 11-piece place set to five pieces and thereby reducing costs. Mellor worked for the
Midlands engineering firm Abacus Municipal on the design of
street lighting, bus shelters, public seating and litter bins. Around 140,000 of his bus shelters having been installed since they were first produced in 1959. In 1965 as part of the
Worboys Committee, he was commissioned by the
Department of the Environment to redesign the national
traffic light system as part of an overhaul of traffic signs. Mellor's redesigned traffic lights are still in use. ==Manufacturing==