The invention relates to a chisel-type working tool which can be mounted to an agricultural vibration combiner provided with supports for active tools intended for preparing the germination bed. According to the invention, the chisel is made of deep drawn platband with a concave working surface, resulting in two linear surfaces (1), two curved surfaces (2) which represent the contact zone with the working support before and after assembling and an arched surface (3) having a radius (R) located between the two curved surfaces (2), which represents a flexible part which changes its shape after assembling and becomes a surface (4) identical to the surface of the working support, a screw (5) being used for mounting it onto the working support while providing mounting safety and stability during work.