Numerically Controlled (NO) machines have in recent years revolutionized the production process, but their productivity may yet be increased by the application of new theory to the controlling computer software. This paper describes the improvement in productivity of a class of NC punch presses which operate from either an off-line computer prepared tape or under direct numerical control. The problem of tool selection and table motion during the manufacture of a product by punching an array of holes in a metal sheet with a sequence of various size and shape tools is formulated as a travelling salesman problem (TSP). Two TSP heuristics, one old and one proposed by the authors, are employed in a comparison test with the.NC press manufacturer's heuristic. Both TSP heuristics generally outperform the manufacturer's heuristic by 10% or more.