The invention relates to the field of agricultural mechanization and can be used in mowers and reapers for mowing grasses and cereals, for example. The task of the present invention is such an improvement of the knife, made as at least a two-blade flat propeller whereby a possibility is achieved to remove or substitute thereof without disassembling the entire shaft by means of improving the design of the knife and parts thereof, and also the regular operation of the mower is provided without mounting special coils for throwing over the mown vegetable mass behind the mower on shaft thereof, significantly simplifying exploiting and servicing the mower. According to the invention, the knife is made at least of two parts, which are separated and connected between each other by area thereof passing along the axle of the shaft of the mower, on which said knife is mounted. In doing so each of the stated parts of the knife has at the place of connecting thereof between each other two brackets, arranged on the both sides from the shaft and made as flat plates, bent in parallel to the stated plane, by which those parts are connected between each other, for example by a bolted connection, and which simultaneously serve as blades for throwing over the mown vegetable mass behind the mower while it is operating. Hubs of the both stated parts of the knife together with the stated brackets are additionally tightened between each other and pressed to the shaft by a corresponding collar, which is also made of two parts, separated between each other by said plane. Each of the stated parts of the knife is put onto its part of the stated collar, pressed thereto and tightened on the shaft by a bolted connection, providing an easy removal of the knife from the shaft without removing and disassembling the latter, for example by simple untightening the bolts tightening the both parts. The presence on the both parts of the knife of the stated brackets as the flat plates, gives the additional
