Abstract: A linear guideway, a sliding module thereof, and a circulation seat thereof are provided. The circulation seat has an inherently one-piece structure, which includes two turning portions, a middle retaining portion, and two lateral retaining portions. The middle retaining portion has a two-stepped structure, which includes a connection bar and a limiting bar that is connected to the connection bar. The connection bar is connected to and arranged between the two turning portions, and a distance between two long lateral surfaces of the connection bar gradually increases along a direction away from the limiting bar. The two lateral retaining portions are connected to and arranged between the two turning portions, and the two lateral retaining portions are respectively located at two opposite sides of the middle retaining portion.

Abstract: A linear guideway, a sliding module thereof, and a circulation seat thereof are provided. The circulation seat has an inherently one-piece structure, which includes two turning portions, a middle retaining portion, and two lateral retaining portions. The middle retaining portion has a two-stepped structure, which includes a connection bar and a limiting bar that is connected to the connection bar. The connection bar is connected to and arranged between the two turning portions, and a distance between two long lateral surfaces of the connection bar gradually increases along a direction away from the limiting bar. The two lateral retaining portions are connected to and arranged between the two turning portions, and the two lateral retaining portions are respectively located at two opposite sides of the middle retaining portion.

Abstract: A pre-treating solution for electroplating zinc alloy surface contains copper ions, hydroxyl ions, a complexing agent and an additive, wherein the additive is selected from sodium phosphate, sodium hypophosphite, phosphoric acid and dissolvable salts of phosphoric acid. The zinc alloy is dipped in the pre-treating solution and electroplated with a copper coating layer. Then, the zinc alloy is further dipped in a copper sulfate solution for thickening the copper coating layer and lastly coated with an anti-corrosion metal layer. Thereby, zinc alloy has excellent anti-corrosion and anti-wearing efficiency and varnish appearance. Moreover, the pre-treating solution contains no cyanide and thus is low toxic and safe to operator during electroplating and to environment after discharging.