The article is devoted to the Russian-Arabic translation, a particular theory of which has not been developed in domestic translation studies to the extent that the mechanisms of translation from and into European languages are described. In this regard, as well as with the growing volumes of Russian-Arabic translation, the issues of this private theory of translation require significant additions and new approaches. The authors set the task of determining the means of translation (cognitive and mental operations and language transformations) that contribute to the achievement of the most equivalent correspondences of such typologically different languages as Russian and Arabic. The work summarizes and analyzes the accumulated experience of modern Russian linguists, Arabists (Belkin V.M., Gabuchan G.M., Grande B.M., Finkelberg N.D., Frolov V.D., etc.) and representatives of the Arabic classical linguistic school (Ibn Jinni, Sibawayh, etc.) in determining the carrier of word-formation meaning. The purpose of the study is designated as the description of the role of this category in achieving equivalence in the pair of Russian and Arabic. The lexical-semantic group of tools and instruments was considered as a material. These lexemes, both in Russian and Arabic, have an acceptable frequency, cover various stylistic registers and are formed by a relatively limited set of formants, interlingual correspondences of which can be established and compared. For the first time, on the material of this lexico-semantic group, a systemic interlingual correlation of the series of word-building formants in Russian and Arabic is revealed. The authors draw conclusions about the category of the word-formation model as a key one in the algorithm of translation activity, as well as about the specific linguistic signs of the equivalence of the Arabic-Russian translation (full transfer of the real meaning of the motivating base, the coincidence of the rhythm of the derived Arabic word with a model, the correspondence of the derivative to the grammatical categories contained in the model).