The invention relates to a cracking-shelling mechanism for nuts with a hard or soft shell, with a plurality of first and second blocks the facing sides of which have a plurality of complementary first and second notches in a staggered arrangement, wherein each first notch is associated with at least a second notch and forms a cracking hole with each one, wherein the notches have first and second vertexes for each hole, forming a specific angle with respect to the longitudinal axis, and in the standby position of the first block, said first and second vertexes of each first notch are arranged so as to coincide with second and first vertexes, respectively, of a second notch.