A drill string rod includes an elongate central rod portion. The central rod portion has a hollow-cylindrical shape with an inner first diameter (drod) and an outer second diameter (Drod). The male end includes a spigot having a base projecting axially from a shoulder that axially separates the spigot and the central rod portion. The female end has a sleeve portion that fits to the spigot. An inner thread of the sleeve portion is attachable to an outer thread of the base of the spigot of a further drill string rod. In a radial plane to the longitudinal axis of the drill string rod, the base of the spigot is defined by an outer third diameter (Dspigot) and an inner fourth diameter (dspigot) and the sleeve portion is defined by an outer fifth diameter (Dsleeve) and an inner sixth diameter (dsleeve), wherein the second diameter (Drod) is >60 mm.