The alloy can not be hardened by heat treatment. It is annealed in the 1600 – 1650°F (871 – 899°C) range and then air cooled to relieve cold working stresses. 410S should not be exposed to temperatures of 2000°F (1093°C) or above due to embrittlement. If excessive large grains are encountered after annealing mildly cold-worked material, the annealing temperature should be decreased to a range of 1200 – 1350°F (649 – 732°C) range.