Feed unit for an automatic saw cutting machine for cutting tubes (T1, T2) in double-tube cutting mode, the feed unit comprising a first pair of motor-driven lower rollers (12a, 12b), that is to say, an upstream slower roller and a downstream lower roller, respectively, for moving first tubes forward along a first feed axis, a second pair of motor-driven lower rollers (14a, 14b), that is to say, an upstream lower roller and a downstream lower roller, respectively, for moving second tubes forward along a second feed axis parallel to the first feed axis, a first pair of upper rollers (16a, 16b), that is to say, an upstream upper roller and a downstream upper roller, respectively, for urging said first tubes against said first pair of lower rollers (12a, 12b), a second pair of upper rollers (18a, 18b), that is to say, an upstream upper roller and a downstream upper roller, respectively, for urging said second tubes against said second pair of lower rollers (14a, 14b), a plurality of first side rollers for retaining laterally said first tubes, and a plurality of second side rollers for retaining laterally said second tubes, wherein the upstream rollers (12a, 14a) of said first pair of lower rollers (12a, 12b) and of said second pair of lower rollers (14a, 14b) are rotatably mounted about a first transverse axis of rotation (y a), wherein the downstream rollers (12b, 14b) of said first pair of lower rollers (12a, 12b) and of said second pair of lower rollers (14a, 14b) are rotatably mounted about a second transverse axis of rotation (y b) parallel to said first transverse axis of rotation (y a), wherein the upstream rollers (16a, 18a) of said first pair of upper rollers (16a, 16b) and of said second pair of upper rollers (18a, 18b) are rotatably mounted about a third transverse axis of rotation (y' a) parallel to said first transverse axis of rotation (y a), wherein the downstream rollers (16b, 18b) of said first pair of upper rollers (16a, 16b) and of said second pair of upper rollers (18a, 18b) are rotatably mounted about a fourth transverse axis of rotation (y' b) parallel to said first transverse axis of rotation (y a), and wherein each upper roller (16a, 16b, 18a, 18b) is adapted to be moved towards a respective lower roller (12a, 12b, 14a, 14b) to clamp a respective tube (T1, T2) against said lower roller (12a, 12b, 14a, 14b), characterized in that said first transverse axis of rotation (y a) is inclined by an angle of inclination (α) between 0° and 60°, limits included, to the horizontal, and in that it further comprises a separating element alternatively movable between a rest position, in which it is wholly placed below the plane passing through said first and second feed axes (x1, x2) and therefore it is not interposed between said first and second tubes (T1, T2), whereby said first and second tubes (T1, T2) are in contact with each other, and a working position, in which it is placed between said first and second tubes (T1, T2) so as to prevent these tubes from being in contact with each other. a first pair of motor-driven lower rollers (12a, 12b), that is to say, an upstream slower roller and a downstream lower roller, respectively, for moving first tubes forward along a first feed axis, a second pair of motor-driven lower rollers (14a, 14b), that is to say, an upstream lower roller and a downstream lower roller, respectively, for moving second tubes forward along a second feed axis parallel to the first feed axis, a first pair of upper rollers (16a, 16b), that is to say, an upstream upper roller and a downstream upper roller, respectively, for urging said first tubes against said first pair of lower rollers (12a, 12b), a second pair of upper rollers (18a, 18b), that is to say, an upstream upper roller and a downstream upper roller, respectively, for urging said second tubes against said second pair of lower rollers (14a, 14b), a plurality of first side rollers for retaining laterally said first tubes, and a plurality of second side rollers for retaining laterally said second tubes,