grading vs scaling

grading and scaling both are nouns.

Word	Noun	Adjective	Verb	Adverb
grading	Yes	No	No	No
scaling	Yes	No	No	No

As nouns, grading and scaling are synonyms defined as:

grading (noun)	scaling (noun)
the act of arranging in a graduated series	act of measuring or arranging or adjusting according to a scale
evaluation of performance by assigning a grade or score	the act of arranging in a graduated series
changing the ground level to a smooth horizontal or gently sloping surface	ascent by or as if by a ladder