Minimum speed to avoid being heat treated

Heat treating is a group of industrial and metalworking processes used to alter the physical,The trapped atoms prevent the crystal matrix from completely changing into its low temperature. Total case depth, min. Salt baths utilize a variety of salts for heat treatment, with cyanide salts being the most extensively used

(-4,0) (3,-5) I don't know if they mean two ordered pairs so I'm pretty sure this is right