The paper continues the idea of the previous work: "Knowledge models in Engineering Technology and Manufacturing" were knowledge models, data models and the knowledge components explicit, implicit, tacit and surface knowledge were presented. The present paper is regarding a specific example of knowledge model: Optimum semi-finished part choosing for straight axes design. The main stages in knowledge model construction will be presented. Also, the solution it will take the shape of a concept map which will be also analyzed from construction. Both knowledge models and concept maps will be treated at two levels: a general one and a particular on the proposed example.