Variation of the pith-bark friction coefficient of the species Quercus cubana A. Rich in Pinar del Rio

The species Quercus cubana A. Rich is the only true oak of the flora of Cuba, already recognized as Cuban endemic, exclusive of the west of the country, limited only to Pinar del Río and with a widespread use in rural life, because its fruits, commonly called acorns, are used as animal food for pigs because they have a high fat content, and its wood is useful in obtaining charcoal to make food. The research was carried out in three moments, starting from the selection of the individuals, using the Quercus cubana A. Rich species, which for its complexities has made difficult the introduction of this one in the industry of secondary transformation of the wood. The objective has been to determine the behaviour of the friction coefficient of this species on surface of wood and metal, obtaining as a result the existing variation between the different sections of the pith towards the bark.