In the production of qualified steel, if 5–30 ppm boron is present in the product, the hardenability of the steel increases significantly by the case hardening process. This small amount of boron content reduces the austenite grain size (by preventing grain growth) and increases the matrix hardnessHardness through the precipitates formed. With the addition of boron, it is possible to obtain the desired hardnessHardness depth due to the cementation applied especially in gear parts. This result obtained in boron steels is similar to Cr, Mn, MoMo(VI) ions, Ni, etc., which are used in conditions where boron is not used. In other words, the use of boron as a microalloying element also provides cost savings. In this study, the parameters affecting the hardenability of steel by boron addition amounts in steel production using ferroboronFerroboron were investigated on the basis of chemical content, metallographic structure, and mechanical propertiesMechanical properties.