Cloud manufacturing is an emerging manufacturing model. It provides organizations with the ability to virtualize their manufacturing resources and offer them as scalable cloud-based services. Tool selection is a crucial function for machining operations. It determines whether a consumer’s manufacturing task can be realized in a machining system. This paper proposes a system for carrying out tool selection for a typical cloud manufacturing system. It uses an ontology to store information about manufacturing resources and automatically generates queries for searching suitable tools in the ontology according to a customer’s specification. The searching of the tools is carried out by a reasoner on the ontology. From the tools that match the user’s requirements, the system selects the most appropriate tool according to the user’s preferences. © Springer Science+Business Media Dordrecht 2014.