An open nut, comprising: an axial cylinder having an axial opening, wherein the axial cylinder has a first axial wall and a second axial wall on two opposite sides of the axial opening, and the axial cylinder comprises an inner circular wall and an outer circular wall, wherein the inner circular wall has a plurality of inner spiral channels; an open shield coaxially fitted over an outer periphery of the axial cylinder, wherein the open shield has an inner peripheral wall, wherein the inner peripheral wall and the outer circular wall of the axial cylinder correspond to each other and form an outer ball race; and two circulators respectively disposed on the first axial wall and the second axial wall, wherein each of the circulators comprises: an inner member comprising a main body, a plurality of through holes, and a plurality of through slots, wherein the through holes and the through slots are disposed in the main body, the through holes and the through slots are disposed in a one-to-one correspondence, and the through slots are provided on a long side of the main body; and an outer member assembled to the inner member correspondingly, wherein the outer member comprises a plurality of arc-shaped sliding grooves, wherein a first end of each of the arc-shaped sliding grooves corresponds to the corresponding through hole, a second end at an opposite side of each of the arc-shaped sliding grooves corresponds to the corresponding through slot, and wherein the inner member and the outer member form a ball race after the inner member and the outer member are combined with each other; wherein one end of each of the through holes of the inner member away from the outer member corresponds to the outer ball race, the through slots of the inner member and the arc-shaped sliding grooves of the outer member are respectively in communication with the inner spiral channels, and one of the inner spiral channels, the ball races of the two circulators, and the outer ball race form a ball circulating race; wherein the outer member further comprises a plurality of guiding protrusions, wherein each of the guiding protrusions corresponds to and extends toward the second end of the corresponding arc-shaped sliding groove; wherein each of the guiding protrusions has an arc-shaped surface, wherein the arc-shaped surface corresponds to a radian of the arc-shaped sliding groove and bends toward the inner spiral channel. an axial cylinder having an axial opening, wherein the axial cylinder has a first axial wall and a second axial wall on two opposite sides of the axial opening, and the axial cylinder comprises an inner circular wall and an outer circular wall, wherein the inner circular wall has a plurality of inner spiral channels; an open shield coaxially fitted over an outer periphery of the axial cylinder, wherein the open shield has an inner peripheral wall, wherein the inner peripheral wall and the outer circular wall of the axial cylinder correspond to each other and form an outer ball race; and two circulators respectively disposed on the first axial wall and the second axial wall, wherein each of the circulators comprises: an inner member comprising a main body, a plurality of through holes, and a plurality of through slots, wherein the through holes and the through slots are disposed in the main body, the through holes and the through slots are disposed in a one-to-one correspondence, and the through slots are provided on a long side of the main body; and an outer member assembled to the inner member correspondingly, wherein the outer member comprises a plurality of arc-shaped sliding grooves, wherein a first end of each of the arc-shaped sliding grooves corresponds to the corresponding through hole, a second end at an opposite side of each of the arc-shaped sliding grooves corresponds to the corresponding through slot, and wherein the inner member and the outer member form a ball race after the inner member and the outer member are combined with each other; an inner member comprising a main body, a plurality of through holes, and a plurality of through slots, wherein the through holes and the through slots are disposed in the main body, the through holes and the through slots are disposed in a one-to-one correspondence, and the through slots are provided on a long side of the main body; and an outer member assembled to the inner member correspondingly, wherein the outer member comprises a plurality of arc-shaped sliding grooves, wherein a first end of each of the arc-shaped sliding grooves corresponds to the corresponding through hole, a second end at an opposite side of each of the arc-shaped sliding grooves corresponds to the corresponding through slot, and wherein the inner member and the outer member form a ball race after the inner member and the outer member are combined with each other; wherein one end of each of the through holes of the inner member away from the outer member corresponds to the outer ball race, the through slots of the inner member and the arc-shaped sliding grooves of the outer member are respectively in communication with the inner spiral channels, and one of the inner spiral channels, the ball races of the two circulators, and the outer ball race form a ball circulating race; wherein the outer member further comprises a plurality of guiding protrusions, wherein each of the guiding protrusions corresponds to and extends toward the second end of the corresponding arc-shaped sliding groove; wherein each of the guiding protrusions has an arc-shaped surface, wherein the arc-shaped surface corresponds to a radian of the arc-shaped sliding groove and bends toward the inner spiral channel.