Mechanical treatment of castings is primarily used in manufacturing of critical parts with high dimensional and geometric accuracy. Investment casting can be used to reduce the specific content of metal and production time. Casting defects are the result of thermophysical impact at various stages of technological process and usually reduce casting accuracy. Forming investment patterns by compacting wax-like powder helps to rectify shrinkage cavities which increases pattern accuracy by 1-2 tolerance grades. In a number of cases the geometry of such pressings is distorted as the result of pressing overcompaction due to material's elastic response. The search for an adequate mathematical model of wax-like powder material compaction process determines the relevance of using finite element method to predict stress-strain state of pressings. The paper presents a comparative analysis of design values and experiment results.