Electric screw terminal comprising: - a metal cage through which there passes an elongate passage intended to accept a connection lug of an electrical device and comprising a tapped orifice passing through a wall of the said cage, and - a telescopic screw passing through the tapped orifice and comprising: - at least a first cylindrical portion having an external screwthread intended to engage with the tapped orifice and having an internal screwthread intended to engage with an external screwthread of at least a second cylindrical portion, - an operating head comprising a drive profile intended to engage with an external tool for operating the telescopic screw, - a clamping head intended to clamp an electrical conductor and the connection lug, characterized in that the operating head comprises a single drive profile positioned at a first end of the said at least one second cylindrical portion, the said drive profile being intended to engage with an external tool so as to drive together in rotation the said at least first and second portions (7A, 7B) via drive means, the said drive means comprising a deformable elastic means interposed between the said at least one first portion and the said at least one second portion and being able to deform so as to secure the said portions together, the clamping head being positioned at a second end of the said at least one second cylindrical portion. - a metal cage through which there passes an elongate passage intended to accept a connection lug of an electrical device and comprising a tapped orifice passing through a wall of the said cage, and - a telescopic screw passing through the tapped orifice and comprising: - at least a first cylindrical portion having an external screwthread intended to engage with the tapped orifice and having an internal screwthread intended to engage with an external screwthread of at least a second cylindrical portion, - an operating head comprising a drive profile intended to engage with an external tool for operating the telescopic screw, - a clamping head intended to clamp an electrical conductor and the connection lug, characterized in that the operating head comprises a single drive profile positioned at a first end of the said at least one second cylindrical portion, the said drive profile being intended to engage with an external tool so as to drive together in rotation the said at least first and second portions (7A, 7B) via drive means, the said drive means comprising a deformable elastic means interposed between the said at least one first portion and the said at least one second portion and being able to deform so as to secure the said portions together, the clamping head being positioned at a second end of the said at least one second cylindrical portion. - at least a first cylindrical portion having an external screwthread intended to engage with the tapped orifice and having an internal screwthread intended to engage with an external screwthread of at least a second cylindrical portion, - an operating head comprising a drive profile intended to engage with an external tool for operating the telescopic screw, - a clamping head intended to clamp an electrical conductor and the connection lug,