The manufacturing industry uses different methods to join metal structures. One widely used method is welding, which usually involves generating heat up to temperatures above the melting point of the base metals. These high temperatures affect the microstructure of the materials and, therefore, the mechanical properties are modified. This variation is not contemplated in the design calculations of the parts where welding is applied. For this reason, in this work, different carbon structural steel specimens were subjected to a gas metal arc welding process. The specimens were designed to perform the procedures of American Society for Testing and Materials standards, which will provide tensile strength and hardness. Consequently, the data obtained from the experimentation were applied to find a correlation between these two mechanical properties to establish a basis for future designs.