Timber as a renewable source has been extensively applied among European countries in the construction field. Among more than 1000 available wood species which could be potentially applied as engineered wood, tropical hardwood takes up a significant portion and has advantages of high mechanical resistance and remarkable biological durability against micro-organisms compared to coniferous species and European grown hardwood. Okan has been part of this development, as a hardwood species mostly from the West African regions.The objective of this thesis is to investigate the strength influencing features, calculate corresponding characteristic values and establish the correlation between the influencing factors and the bending strength with the least deviation and create a representative Okan strength predicting model. Abstracted from literature and dataset, geographically speaking, climate, precipitation, soil quality, water sources are expected to have varying degrees of impacts on mechanical properties. From the material perspective, knot ratio, fiber orientation (slope of grain & ring angle), moisture content, density, Modulus of elasticity (dynamic, static) are important factors. Several experiments about hardwood bending strength have been conducted. However, none of those focus on the growth ring angle and the 3D effect of the fiber orientation. To dive deep into Okan, a series of laboratory tests are conducted, including non-destructive inspection, a four-point bending test on 20 beams (10 stored in the dry condition, 10 stored in the wet condition) with the assistance of digital image correlation technology [DIC]). Except for the regulated experimental procedure, two innovative visual inspection methods based on image processing via Matlab were conducted and verified, which turns out the automation method has preferable efficiency and precision. However, this method could hardly identify compression failure. To avoid the compression failure, beams with the dynamic modulus of elasticity less than 18500 N/mm^2 are supposed to be checked again by the inspector. All possible influencing factors are well determined by the above-mentioned testing.Influencing factors of the fracture section form could be concluded from the observation of damaged samples. The slope of grain and growth ring work together to determine the form of the governing crack section. From the experimental outcome, it is clear to observe the linear correlation between mechanical properties and moisture content grouped by the slope of grain. Constant k= 0.13 for bending strength is found, k = 0.05 is found for dynamic modulus of elasticity. The experimental results yield the following adjusted characteristic values: bending strength 63.56 N/mm^2, dynamic modulus of elasticity 21134.55 N/mm^2, density 866.58 kg/mm^3. Based on 20 beams, this batch of Okan could be graded to D55 which is higher than D30-D35 yielded from the dataset. Besides, Okan beams from Gabon could also be graded into D55. Current European standards advise that the reasonable slope of grain range for tropical hardwood is 0 to 0.1. Through the calculation of the theoretical slope of grain of the dataset and experimental samples, increasing the threshold of the slope of grain to 0.3 should be considered in the testing program. Further promotion to 0.2 doesn’t improve the grading outcome and even worsen it.The linear regression result of modulus of elasticity and bending strength is more preferable than density and bending strength in literature and experimental results, which proves the modulus of elasticity is a good indicator of bending strength. Large scatter happens in the regression of the Hankinson formula. In the combination of two basic models, the new proposed model has an optimized coefficient of determination (R^2 = 0.685). The distribution function of the bending strength of the dataset has preferrable overlapping with the theoretical bending strength calculated from the new strength model. To keep the model on the safe side, a safety factor y = 0.9 is applied.It is still unclear if the growth ring angle has a clear numerical relationship with mechanical properties. However, the growth ring angle does bring apparent influences on the form of the fracture section. The 3D effect of fiber orientation needs further investigation.