The collaborative re-use of design and manufacturing data is one way that e-commerce can significantly reduce costs and lead times of new products in a demanding global market. This paper describes the development of a 3D Internet-based search engine, which will allow designers to locate parts already in production that have a similar shape to a desired 'newly designed' part. The project anticipates a time when manufacturers will post 3D computer-generated models of their product range on the Internet as a means of advertising their production capabilities (i.e., tooling). The models will either be uploaded to, or harvested from anywhere in the world by, the search engine, which will then analyse the models and store relevant feature indices in a database. To use the system a designer would upload a model of the desired part. The search engine then analyses the shape characteristics of the target model and performs a similarity match through a sieving technique as described in this paper. As a result, the designer is presented with a number of parts similar to the one uploaded. The designer may then modify the design to incorporate the closest matching part, or contact the company to quote for the original target model, as a variant of their existing product. The challenge of the research is to identify the key shape characteristics that produce meaningful representations of the 3D models for similarity comparison purposes. After reviewing the current literature on shape matching and describing the system architecture, this paper presents initial results of the matching capabilities of the search engine.