Answer :
Dressing is focused on the abrasive grains, while truing is focused on the wheel's overall shape and geometry in grinding wheels and metals prone to overheating and reaction with oxygen, should not be ground on pedestal grinders.
a) In reference to grinding wheels, dressing and truing are two distinct processes. Dressing refers to the process of removing the bonded abrasive grains from the surface of the grinding wheel, exposing fresh abrasive grains and restoring the wheel's cutting ability. It is done to maintain the wheel's shape and sharpness. Truing, on the other hand, involves reshaping the grinding wheel to its original profile. It is done to restore the wheel's geometric accuracy and correct any irregularities or deviations in its shape.
b) Certain types of metals, particularly those prone to overheating and reaction with oxygen, should not be ground on pedestal grinders. Examples include magnesium and aluminum. Grinding these metals can generate high temperatures and sparks, increasing the risk of ignition or explosion due to their flammability. Moreover, the fine metal particles produced during grinding can also pose a fire hazard. To mitigate these risks, alternative methods such as cold cutting or using specific grinding equipment designed for these metals should be employed.
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