Abstract
From the symmetry point of view 55 species of full ferroelastic phase transitions in nonferromagnetic crystals with full ferroelastic properties have been considered. It has been shown that 34 species of full ferroelastics are full ferrobielastics at the same time. But if the paraelastic phase is noncentrosymmetric one (21 species), then full ferroelastics are full ferrobielastics and full ferroelastoelectrics. Also the possibilities of the orientation states (domains) switching in such ferroics are discussed. As example, full ferroelastic K2Cd2(SO4)3 (23 → 222) with langbeinite type structure is considered.