Cut point
In fractional distillation a cut point is the temperature that defines the boundary between two crude oil fractions that are being separated.
For the lighter fraction, the cut point represents the end point, or temperature below which all of the light fraction components boil. For the heavier fraction, the cut point represents initial boiling point or temperature above which all of the heavier fraction's components boil.
Refiners can adjust the yield of two adjacent fractions by adjusting the cut point, and thereby generating more of one fraction and less of the other. The range across which the refiner typically swings the cut point is called the swing cut.