Slide rail kit

1 . A slide rail system, comprising:

a rack having a first side frame and a second side frame, wherein each of the first side frame and the second side frame comprises at least one post; and

a slide rail kit comprising:

a first rail having an outer side and an inner side;

a second rail longitudinally movable relative to the first rail and adjacent to the inner side of the first rail; and

a bracket device arranged on the first rail and comprising a rack mounting feature;

wherein a recessed structure is formed at the outer side of the first rail and recessed toward the inner side of the first rail;

wherein the post of the first side frame has a predetermined part arranged along a transverse direction of the slide rail kit and formed with a corresponding hole;

wherein the first rail is configured to be mounted to the post of the first side frame of the rack through inserting the rack mounting feature of the bracket device along a longitudinal direction of the slide rail kit into the corresponding hole of the predetermined part, wherein when the rack mounting feature of the bracket device is inserted into the corresponding hole of the predetermined part, at least a portion of the predetermined part of the post of the first side frame is configured to be extended into the recessed structure of the first rail along the transverse direction of the slide rail kit to be accommodated within the recessed structure, and the rack mounting feature of the bracket device is adjacent to the recessed structure of the first rail.

2 . The slide rail system of claim 1 , further comprising a third rail movably mounted between the first rail and the second rail; wherein the first rail comprises a first wall, a second wall and a longitudinal wall connected between the first wall and the second wall, and a passage is defined by the first wall, the second wall and the longitudinal wall of the first rail to accommodate the third rail.

3 . The slide rail system of claim 2 , wherein the recessed structure is partially formed on the longitudinal wall and located at the outer side of the first rail.

4 . The slide rail system of claim 3 , wherein the recessed structure is partially formed on at least one of the first wall and the second wall of the first rail.

5 . The slide rail system of claim 1 , wherein the recessed structure is formed on a predetermined rail section of the first rail.

6 . The slide rail system of claim 3 , wherein the longitudinal wall has a plurality of first surfaces and a second surface at the outer side of the first rail, and the second surface is located between the first surfaces; wherein the first surface and the second surface are spaced apart from each other by a transverse distance along the transverse direction of the slide rail kit, wherein the recessed structure is recessed relative to the first surface and the second surface is a bottom surface of the recessed structure.

7 . The slide rail system of claim 6 , wherein the first surface and the second surface are located at different transverse positions along the transverse direction of the slide rail kit.

8 . The slide rail system of claim 6 , wherein the longitudinal wall of the first rail comprises a first longitudinal section, a second longitudinal section and a rib connected between the first longitudinal section and the second longitudinal section; each of the first longitudinal section and the second longitudinal section has the first surface, and the rib has the second surface.

9 . The slide rail system of claim 1 , wherein the first rail has a first end part and a second end part opposite to each other; wherein the recessed structure is located adjacent to one of the first end part and the second end part.