The objective of design for manufacture is to sever the dichotomy of design and manufacturing practices so that these two areas will be pursued as a homogeneous activity. Many issues are important for this “marriage” of design and manufacturing: the representation of manufacturing information for reasoning in the early stages of a design; the development of computer-aided tools for process planning, tolerance design and analysis, and automatic assembly; the formulation of design systems to facilitate reasoning about the topology and geometric structure of mechanical parts; etc. In this paper, a strategy for the representation and manipulation of spatial relationships between features is described. A language, made up of a set of primitives (lexical icons and geometric concepts), is developed for the domain of standard cavity-type features encountered in discrete parts manufacturing. A formal methodology is subsequently discussed for modeling these features in the context of interacting and interfeature relationships. Two applications, in the areas of fixture design and process planning, illustrate the utility of the formalism.