(EN) The robot arm is coupled to one joint section (100) and consists of an elbow having driving gears (10,12,14), an arm (120) and a wrist (130). The arm comprises three concentric tubes (30,32,34) and its length has a selection of values, corresponding to the application. The arm is detachable and attached to the joint with pins (40,42) and bolts (56). It is also connected to the wrist with pins (48,50) and bolts (58). The driving rotary force from the driving gears is transmitted to the wrist through the pipes (30,32,34) and the gears (66,68).