The tensioner used to tension the blades for cutting granite blocks and installed on granite gangsaws is a hydraulic modular device (patented) specially designed to distribute the same tension on all blades of the gangsaw. So, it avoids all the manual tensioning procedures with the great advantage of easily equipping and discussing the gangsaw. Hydraulic tensioners for granite are available in 8mm and 10mm minimum cut with three rains of pistons and for 15mm and 20mm minimum cut with two rows of pistons.