粘度等级对照表 viscosity classification equivalents
many petroleum products are graded according to the iso viscosity classification system, approved by the international standards organization (iso). each iso viscosity grade number corresponds to the mid-point of a viscosity range expressed in centistokes (cst) at 40°c. for example, a lubricant with an iso grade of 32 has a viscosity within the range of 28.8-35.2, the midpoint of which is 32.
rule of thumb: the comparable iso grade of a given product whose viscosity in sus at 100°f is known can be determined by using the following conversion formula: sus @ 100°f ÷ 5 = cst @ 40°c