Low carbon titanium steels with nickel and/or manganese and silicon additions were developed to combine formability, nitradability with increased strength. The strength, formability, and nitradability of 16 different compositions were investigated. Neither the depth nor the great hardness of nitrided layers, due to TiN particles < 15A in size, was influenced by the addition of other alloying elements. The high nucleation frequency resulting in the small size of TiN particles is attributed to the coprecipitation of TiN and Fe4N minimizing the strain energy barrier for nucleation. The hardening caused by various volume fractions of TiN precipitate in the nitrided layer was in good agreement with the quantitative estimate of Gerold and Habercorn15 in which the interaction between edge dislocations and coherency strain fields is assumed to be the strengthening mechanism.