Öz
Today, there are patented heat treatment methods using different methods in various countries. One of these methods is the ThermoWood method. It is a known fact that many properties of wood (mechanical, physical, chemical, biological, etc.) change as a result of the change in the structure of wood with heat treatment. At the beginning of these features, the concept of hardness emphasizes an important issue for wood. In this study, the Shore D hardness values of maple, common alder, rowanberry, chestnut, hornbeam, Uludağ fir, willow, Strendzha Oak, and ash woods that occur at 212oC for 1 and 2 hours after and before heat treatment were investigated according to the ThermoWood method. According to the results of the research, variance analysis results were obtained as significant. The highest reduction rate among wood species was obtained in Uludağ fir, which was heat-treated at 212oC for 2 hours, while the lowest was determined in common hornbeam wood, which was heat-treated at 212oC for 1 hour. It was determined that the hardness values of all tree species decreased with heat treatment. In addition, it was shown that the results decreased with the increase of the heat treatment time.