Mechanical properties are essential when using wood for building and construction purposes. We determined the impact bending strength of spruce wood (Picea abies L.), and searched for correlations among the impact of bending strength, modulus of elasticity and strength. We also determined the effect of density and ring width on the impact bending strength. The specimen consisted of 100 boards and 100 spruce planks, with a known modulus of elasticity and strength. To test the impact bending strength according to DIN 52189 2 samples free of defects were cut from whole boards or planks. The results show some weak link among the test results of the whole samples compared to those cut ones to determine the impact bending strength. We confirmed the correlation among density, ring width and impact bending strength.