C--Coefficient of friction over 0.05 but not over 0.15.
D--Coefficient of friction over 0.15 but not over 0.25.
E--Coefficient of friction over 0.25 but not over 0.35.
F--Coefficient of friction over 0.35 but not over 0.45.
G--Coefficient of friction over 0.45 but not over 0.55.
H--Coefficient of friction over 0.55.
N.Y. Comp. Codes R. & Regs. Tit. 15 § 53.4