Semi-automatic band saw for straight cuts. Head structure in special aluminium casting alloy. Dynamic blade tensioning with blade break micro switch. Blade cleaning brush is integrated in the head protection cover. Head feeding system with hydraulic cylinder and descent adjustment by flow control valve placed at the front position of the saw. Blade guides with combined action of side bearings, carbide plates and top bearing. Reduction gear box with inclined ground, case hardened teeth lubricated with long lasting grease.