Influence of pine wood (Pinus syhestris L.) thermal modification on the withdrawal force of screws. In the study the force required to withdraw the screw from thermally treated pine wood was examined. Modification of pine wood was performed at a temperature range of 150 - 180°C. It was concluded that the process of wood modification does not significantly affect the force needed to pull a screw out, and therefore also the withdrawal capacity and the ability to maintain the screw. In the case of 3.5 x 35 mm and 4.0 x 35 mm screws, the withdrawal capacity constituted respectively 63% and 50% of the ability to maintain the screw.