Knowledge of the force required to overcome deformation at the proportionality limit, maximum limit, and their ratio, as well as knowledge of the effect of selected factors on the listed characteristics in bending stress, have both scientific and practical significance. They form a foundation for designing tools for bending and determine the stress that products and their parts can be exposed to during use. This study analyzes the effect of selected factors on the force at the proportionality limit (FE), the force at the maximum limit (FP), and the ratio of these two characteristics (FE/FP). This study examined the effect of the wood species (WS) (Fagus sylvatica L. and Populus tremula L.), material thickness (MT) (4 mm, 6 mm, 10 mm, and 18 mm), degree of densification (DOD) (0%, 10%, and 20%), and the number of cycles (NOC) (0 or 10,000), as well as their combined interaction, on the monitored characteristics. The results contribute to the advancement of knowledge necessary for the study and development of new materials with specific properties for their intended use. The results can improve the innovative potential of wood processing companies and increase their performance and competitiveness in the market.