A bolt (1) is adapted to clamp a pin (2) to an external fixator system. Said bolt (1) comprises a shaft having a threaded section (10), a head section (11) and a pin opening (13) that is arranged opposite the threaded section (10) and accommodates and clamps a pin (2) or a wire to a plate (3) of an external fixator. The plate (3) comprises at least one opening (30) which accommodates the shaft and a surface (31) against which the pin or the wire is clamped by means of the bolt (1). Said pin opening (13) comprises at least two edges (15) extending essentially along the same direction as the pin opening (13) such that the pin (2) or wire to be clamped is contact with said edges (15).
