A steering block for the final phase of a guided projectile comprises control jets acted upon by hot gas created in a combustion chamber. A preferred embodiment of more compact and acceleration resistant construction, uses four control jets arranged lying in the cross sectional plane of the projectile casing equidistantly distributed around the circumference of the projectile casing. Each control jet has a corresponding valve likewise arranged lying in a plane in such a way that their longitudinal axes extend along chords of the circular cross section of the projectile casing. In another preferred embodiment, for purposes of further cost reduction in volume and weight, the valves have an adjusting member made of memory alloy which is electrothermically acted upon by way of a heating element.