Problem. To provide a chain pin which makes it possible to improve wear resistance even in an environment in which degraded oil is used. Solution. A large number of pins are mixed/agitated together with a particle mixture including a penetrant comprising chromium (Cr) powder and tungsten carbide (WC) powder, and an iron chloride (FeCl.sub.3) catalyst, and WC particles penetrate the surface of the pins together with chromium carbide (CrC). As a result, a chromium carbide layer in which WC particles are diffused in a CrC layer (CrCWC layer) is formed on the outermost surface part of the steel forming the parent material of the pins.

A method for selectively plating a leadframe (1100) by oxidizing selected areas (401, 402, 403, 404) of the leadframe made of a first metal (102) and then depositing a layer (901) of a second metal onto un-oxidized areas. The selective oxidations are achieved by selective active marking

A method for selectively plating a leadframe (1100) by oxidizing selected areas (401, 402, 403, 404) of the leadframe made of a first metal (102) and then depositing a layer (901) of a second metal onto un-oxidized areas. The selective oxidations are achieved by selective active marking

A large sintered RFeB magnet, a preparation method and use thereof are provided. The sintered RFeB magnet has a thickness not less than 10 mm in an orientation direction. Any cross section along the orientation direction is marked as a diffusion cross-section area, and a side of the diffusion cross-section area close to the outer surface of the sintered RFeB magnet is marked as the surface of the diffusion cross-section area. The difference between the coercivity of the surface of the diffusion cross-section area and the coercivity at 5 mm away from the surface of the diffusion cross-section area is H, and H is 50 kA/m.

A large sintered RFeB magnet, a preparation method and use thereof are provided. The sintered RFeB magnet has a thickness not less than 10 mm in an orientation direction. Any cross section along the orientation direction is marked as a diffusion cross-section area, and a side of the diffusion cross-section area close to the outer surface of the sintered RFeB magnet is marked as the surface of the diffusion cross-section area. The difference between the coercivity of the surface of the diffusion cross-section area and the coercivity at 5 mm away from the surface of the diffusion cross-section area is H, and H is 50 kA/m.