Abstract: A metal-working machine (10) comprises a first machining unit including a machining head (12) and means (11) in the form of a clamp for bringing, holding and axially displacing the material to be machine. The machining head (12) carries tools (13 and 14) which rotate and move relative to two axes X.sub.1 and X.sub.2 perpendicular to the axis (15) of the material. The machine also comprises a main turret (16) equipped with machining stations (17) and stations for receiving (18) the parts. In a first option, it comprises a second machining unit (2) carrying machining stations (23). In a second option, it comprises a third machining unit (24) carrying a machining station (26) equipped with a possibly rotating tool (25). In a third option, the machine is completed by an auxiliary turret (20) carrying a machining station (21).

Abstract: A machining unit, in particular in a numerically controlled lathe, has a rotary head equipped with four pivoting tools for machining parts which pass axially through this head without rotating. Each tool is mounted on a respective pivoting support (6a-6d) provided with a helicoidal guiding surface (26a-26d) the axis of which coincides with the pivoting axis (7a-7d) of the support. The four tools are controlled by means of two concentric annular sockets (30, 42) controlled in translation. The inner socket (30) has two outer surfaces which rest against the guiding surfaces (26a, 26b) of two of the supports. The guiding surfaces are helixes of opposite pitch, and therefore one of the corresponding tools moves toward the part as the second tool moves away from it. The outer socket (42) controls the other two tools in the same manner.