A tradition exists in historical linguistics to use a people s language in order to reconstruct de cultural history of the people. One of the followed methods is lexical reconstruction through the method Wörter und Sachen ( Words and Things ). This method has been applied for the historical reconstruction of several African techniques such as pottery, metallurgy, the fabrication of wood objects, etc. but it clearly poses problems. The introduction of a new technique within a community asks for the creation of an appropriate lexicon. The study of the vocabulary of a recent technique for which we know the origin aluminium casting creates the opportunity to look how such a vocabulary really is constituted and to discern the different factors that play a role in the constitution. Our research shows that the transmission of a technique does not automatically involve the transmission of the vocabulary used by the introducers of the technique. This article gives an outline of the constitution of the lexicon and the factors that influence the process. A process of redenomination is used to form most of the terms. The casters try to find cognitive relations between the new objects and concepts that already exist in the language. The denomination takes place for instance through semantic change, composition or derivation. Besides, a lot of loanwords from French are used or the casters make use of other technical vocabularies they are familiar with. An important characteristic of the aluminium casting vocabulary is the diversity between the lexicons used by several artisans speaking the same language. A number of aspects influence the creation of a personal terminology: the professional trajectory covered by the caster, the aspect of social identity, the (socio)linguistic context that surrounds the caster, etc. The analysis of the aluminium casting vocabulary shows that the choice of words does not only discloses information on the trajectories of the individuals who carry out the technique, but also on the technique itself and on how it is perceived by the adopting community. The conclusions of our research are not only helpful for the study of new lexicons, but may also play a role in the historical analysis of older vocabularies and in the development of vocabularies to accompany new techniques.