“…k = 3 relationship has been proven for coarse-grained polycrystalline materials, speci cally carbon and alloy steels after annealing, normalization, and quenchto-temper conditions. Both experiments and the general theory of the relationship between microscopic hardness and macroscopic strength with reference to microstructure, composition, heat, and mechanical treatment are described in literature [1,16,17,[21][22][23][24]. The reported range of linear coe cient, k, referring to Vickers hardness, is 2.8-3.36 [1,17,23,25].…”