Abstract: The sharpness or efficiency of cutting edges of blade rails or other blades used in mowing mechanisms is very rapidly lost on meeting a obstacle. The blade shape of this invention, presents a cutting edge including a series of adjacent parallel recesses transversely to the cutting edge on the top of the blade. This gives equidistant thin and complete material. A differentiation is made on the cutting edge between the protective material (full thickness) and sharp edges (recesses). Experience has shown that, on the encountering of an obstacle, the cutting edge (thin Material) is protected by the full material to its left and right which results in a long useful life with relatively constant cutting efficiency.