Question: what is the difference in nail file grits?
Answer: Coarse files (80-100 grit) are best for acrylic nail extensions. ... Fine files (240-600 grit) are best for removing small bumps, ridges or discolorations and for shaping the free edge of natural nails. Ultra fine files (600-2400 grit) are used for buffing and shining all types of nails.