 By contrast, discontinuous dynamic recrystallization involves nucleation and growth of new grains, where due to increased temperature and/or pressure, new grains grow at high angles compared to the surrounding grains.Grain strength generally follows the Hall–Petch relation, which states that material strength decreases with the square root of the grain size.A higher number of smaller subgrains leads to a higher yield stress, and so some materials may be purposefully manufactured to have many subgrains, and in this case subgrain rotation recrystallization should be avoided.