Effects of heat treatment on nail and screw withdrawal resistance of some woods

The aim of this study, Scotch pine (Pinus sylvestris L.), Oriental beech (Fagus orientalis Lipsky.), Uludağ fir (Abies bornmülleriana Mattf.) and Carolina poplar (Populus canadensis (Populus nigra x Populus deltoides)) woods at three different temperatures (120, 160, 200ºC), at two different duration (2 ve 6 hour) and at inert (nitrojen) environmet heat treatment to be applied afterwards determined will nail and screw withdrawal resistance.As a result, nail withdrawal resistance values of oriental beech were found higher than the others species. The least nail withdrawal resistance values were found in the Uludağ fir. According to the temperature of heat treatment, nail withdrawal resistance values of 120ºC heat treated samples were found higher. According to the duration of heat treatment, the highest nail withdrawal resistance values were found in the 6 hours heat treated. The least nail withdrawal resistance values were found in the control samples. Nail withdrawal resistance values of radial surface were found higher than the others. The least nail withdrawal resistance values were found in the cutting ends.According to the values obtained in screw withdrawal resistance, screw withdrawal resistance values of oriental beech were found higher than the others species. Screw withdrawal resistance values of hardwood were found higher than the softwood species. According to the condition of heat treatment, screw withdrawal resistance values of control samples were found higher, the least screw withdrawal resistance values were found in the 200ºC heat treated samples. Heat treatment temperature with screw withdrawal resistance is inversely proportional. Duration of heat treatment at screw withdrawal resistance were not more effective. Screw withdrawal resistance values of radial surface were found higher than the others and the least withdrawal resistance values were found in the cutting ends as in nail withdrawal resistance.