The melting point t(s), strength at 20degreesC, and volume shrinkage in the range of ts of hydrocarbons of different classes, model mixtures, and solid petroleum waxes of different industrial grades were investigated. The mechanisms and features of the decrease in these characteristics were revealed for synthetic tetracosan (n-C24H50) and n-alkane concentrate for P-1 alimentary wax on addition of up to 20 wt. % of hydrocarbons from other classes. The strength and plasticity carriers in petroleum waxes were established.