A device for hot forging of a metal article, in particular a flange, said device being provided with: - an anvil and a ram which are located opposite to each other, wherein the ram is arranged to move upward and downward relative to the anvil; - a lower die half mounted to the anvil and an upper die half mounted to the ram; and - a mounting mechanism for mounting the upper die half to the ram, said mounting mechanism being provided with: - a left bolt hole and a right bolt hole (17, 18) in a bottom of the ram; - a protruding edge of the outer wall of the upper die half; - a left and a right mounting plate (24, 25) which are located opposite to each other and substantially parallel to the bottom of the ram, wherein the facing sides of the mounting plates (24, 25) at least partly abut against the protruding edge, wherein each mounting plate (24, 25) is provided with at least one bolt hole, wherein the bolt hole of the left mounting plate is aligned with the left bolt hole and the bolt hole of the right mounting plate is aligned with the right bolt hole; and - a left and a right bolt (22, 23) for mounting the mounting plates (24, 25) to the bottom of the ram by means of said bolt holes (17, 18, 26), characterized in that the mounting mechanism is further provided with: - a left elastically compressible plate situated on a distance from the upper die half and located between the left mounting plate and the bottom of the ram, wherein said left bolt is located in the open space between the left elastically compressible plate and the upper die half; and - a right elastically compressible plate situated on a distance from the upper die half and located between the right mounting plate and the bottom of the ram, wherein said right bolt is located in the open space between the right elastically compressible plate and the upper die half. - an anvil and a ram which are located opposite to each other, wherein the ram is arranged to move upward and downward relative to the anvil; - a lower die half mounted to the anvil and an upper die half mounted to the ram; and - a mounting mechanism for mounting the upper die half to the ram, said mounting mechanism being provided with: - a left bolt hole and a right bolt hole (17, 18) in a bottom of the ram; - a protruding edge of the outer wall of the upper die half; - a left and a right mounting plate (24, 25) which are located opposite to each other and substantially parallel to the bottom of the ram, wherein the facing sides of the mounting plates (24, 25) at least partly abut against the protruding edge, wherein each mounting plate (24, 25) is provided with at least one bolt hole, wherein the bolt hole of the left mounting plate is aligned with the left bolt hole and the bolt hole of the right mounting plate is aligned with the right bolt hole; and - a left and a right bolt (22, 23) for mounting the mounting plates (24, 25) to the bottom of the ram by means of said bolt holes (17, 18, 26), - a left bolt hole and a right bolt hole (17, 18) in a bottom of the ram; - a protruding edge of the outer wall of the upper die half; - a left and a right mounting plate (24, 25) which are located opposite to each other and substantially parallel to the bottom of the ram, wherein the facing sides of the mounting plates (24, 25) at least partly abut against the protruding edge, wherein each mounting plate (24, 25) is provided with at least one bolt hole, wherein the bolt hole of the left mounting plate is aligned with the left bolt hole and the bolt hole of the right mounting plate is aligned with the right bolt hole; and - a left and a right bolt (22, 23) for mounting the mounting plates (24, 25) to the bottom of the ram by means of said bolt holes (17, 18, 26), - a left elastically compressible plate situated on a distance from the upper die half and located between the left mounting plate and the bottom of the ram, wherein said left bolt is located in the open space between the left elastically compressible plate and the upper die half; and - a right elastically compressible plate situated on a distance from the upper die half and located between the right mounting plate and the bottom of the ram, wherein said right bolt is located in the open space between the right elastically compressible plate and the upper die half.