An object of the invention is to provide a blade preferable for being mounted on various kinds of work machines, particularly work machines for digging, carrying of soil and leveling, in which increase in a quantity of soil per tractional force is achieved with a simple structure to reduce consumption horsepower and increase fuel consumption efficiency thereby leading to low cost. A blade comprises a central front face section having a linear first cutting edge at a bottom end thereof, a jointed front face section having a second cutting edge which continues from the first cutting edge and extends backward in an expanding manner at a predetermined angle, and an end front face section having a third cutting edge which continues from the second cutting edge and extended forward in an expanding manner at a predetermined angle. Each blade front face of the central front face section, the jointed front face section and the end front face section is constructed of a continuously curved concave face in upward and downward directions thereof. Preferably, a blade width of the first cutting edge is set larger than an internal width between right and left traveling units or a distance between opposing faces of a pair of right and left brackets for lift cylinders.