Monocortical pin (1) for an external fixator for temporary and/or permanent fixing applications for treating bone fractures and connecting two or more bone fragments together, comprising an elongated cylindrical stem (2) which extends along a longitudinal axis (X) and a conical portion (3) with a tip having an external thread for inserting the pin (1) inside a bone； where said elongated cylindrical stem (2) has a flattened surface (2a) which lies along a reference plane (A) parallel to the longitudinal axis (X) and said conical portion (3) with the tip has an overall length, measured along the longitudinal axis, equal to the diameter (d) of the stem (2) ± 20% of said diameter (d)； said monocortical pin (1) is characterized in that the conical portion (3) comprises a tip (31) which has a centring zone (33) which extends longitudinally over a length equal to 6-8% of the diameter (d) of the stem (2), and a threaded portion (32)； moreover the conical portion (3) comprises a cutting face (34) which extends longitudinally over a length equal to about 40% of the diameter (d) of the stem (2).
