Filter for hydraulic fluids for hydraulic circuits, comprising: - a container exhibiting inside at least one housing compartment fluidically communicating with at least one inlet and at least one outlet associated to said container, the container exhibiting a substantially elongated shape, particularly a cylindrical one, extending along a prevalent development direction between a first and second ends (2a, 2b), - at least one filtering cartridge engageable with the container inside the housing compartment, the filtering cartridge partitioning the housing compartment in a first chamber fluidically communicating with the inlet and a second chamber fluidically communicating with the outlet, the filtering cartridge being configured and positioned for determining the filtering of the hydraulic fluid from the inlet and passing from the first to the second chambers (3a, 3b), the container exhibiting at least one engagement portion projecting inside the housing compartment and defining at least one collar having an outer coupling lateral surface, the filtering cartridge exhibiting a respective engagement portion defining a respective collar exhibiting an inner coupling lateral surface engaging outside the outer coupling surface of the container, said outer and inner coupling surfaces (8, 10) being configured for cooperating with each other to define a removable engagement between the filtering cartridge and container, characterized by the fact that the outer coupling surface of the engagement portion of the container exhibits, along a cross-section, a polygonal shape, the inner coupling surface of the engagement portion of the cartridge being at least partially countershaped to the outer coupling surface of the container and tightly engaging outside the outer coupling surface of the container, the engagement portion of the container extending, from a base, parallelly to the prevalent development direction of the container itself, inwardly the filtering cartridge, the outer coupling surface of the collar of the container exhibiting a first section extending inside the cartridge parallelly to the prevalent development direction of the container, the outer coupling surface of the container exhibiting a second section extending inside the cartridge, without interruption, with respect to the first section, the outer coupling surface of the second section being sloped with respect to the prevalent development direction of the container and converging according to a direction entering the filtering cartridge, wherein the filter comprises at least one seal interposed between the engagement portions (7, 9) of the container and filtering cartridge, respectively, the seal comprising a closed perimetral element configured for defining the fluid tightness between the filtering cartridge and the container, particularly between the engagement portions (7, 9) of the container and filtering cartridge, respectively, wherein the seal is stably supported by the collar of the filtering cartridge and is interposed between the outer and inner coupling surfaces (8, 10) of the container and the filtering cartridge, respectively. - a container exhibiting inside at least one housing compartment fluidically communicating with at least one inlet and at least one outlet associated to said container, the container exhibiting a substantially elongated shape, particularly a cylindrical one, extending along a prevalent development direction between a first and second ends (2a, 2b), - at least one filtering cartridge engageable with the container inside the housing compartment, the filtering cartridge partitioning the housing compartment in a first chamber fluidically communicating with the inlet and a second chamber fluidically communicating with the outlet, the filtering cartridge being configured and positioned for determining the filtering of the hydraulic fluid from the inlet and passing from the first to the second chambers (3a, 3b),