Abstract: A plug connector has an insulative housing, a mounting bracket, multiple first terminals, multiple second terminals and a shell. The mounting bracket is mounted on the insulative housing. The first terminals are mounted through the insulative housing and have soldering sections arranged in a first transverse row. The second terminals are mounted through the mounting bracket and have soldering sections arranged in a second transverse row. The soldering sections arranged in the different rows reduce a density of a soldering section layout and facilitate soldering the plug connector to a PCB.

Abstract: Disclosed is a method for improving the wear- and corrosion-resistance of a chromium-plated steel substrate by heat-treating the chromium-plated steel substrate under optimum conditions to inhibit a drop in corrosion-resistance of a steel substrate due to fine cracks formed at a chromium layer, and to improve a hardness of the chromium layer. The heat-treating method comprises the steps of: plating the chromium layer onto the steel substrate; and heating the chromium-plated steel substrate in an oxidizing gas environment at above atmospheric pressure to form oxidized layers containing magnetite (Fe3O4) on the surface of the steel substrate, the surface of the steel substrate being partly exposed to the air through penetrating cracks formed in the chromium layer.