Portable boring machines are multifunctional machine tools: center-of-center boring (including blind holes), internal and external weld overlay, drilling, tapping, and orthogonal grinding of surfaces and external cylindrical surfaces. These units are perfectly suited to the needs of various sectors (earthmoving, industrial, naval, etc.), avoiding site downtime: by eliminating the need to dismantle the part, transport it, and rework it in the workshop, they significantly save time and costs.