The most common types of seals used to protect bearing arrangements in general industrial applications are radial shaft seals for shaft diameters up to 203 mm (8 in). Large diameter seals, for shaft diameters above 203 mm, have special features and are intended for use in large-size and heavy-duty applications.Turning to application criteria. Industrial shaft seals primarily function to retain lubricant, exclude contaminants (such as dust or moisture), separate media (including lubricant), and resist pressure. Radial shaft seals are the most prevalent types for general and heavy-duty industrial applications.

Radial shaft seals with low cross sectional height: It is not always easy to find commercially available radial shaft seals for bearing arrangements that incorporate needle roller bearings or plain bearing bushings because of their very low cross section.