Felt TypeSAE F-1 A high grade, high density felt recommended for precision uses where maximum durability and resistance to wear are required. Typical uses are: Bearing seals, ink rolls, Polishing pads, Bumpers, Low Viscosity oil retention and feeding as in lubrication wicking, Wiping applications in sheet metal, tube and wire manufacturing. SAE F-2 & SAE F-3 High grade felts of slightly less density and durability than SAE F-1, but still recommended for precision uses such as: Vibration mounts, Precision lubrication wicking, Oil seals, Bumpers, Gaskets, Automobile, Aircraft, and Machinery Components. SAE F-5 A high grade, medium density felt recommended for precision uses where resiliency and durability are important factors. Typical uses are: Lubrication wicks, Grease seals, Wipers, Shock dampers, and Dust seals. SAE F-6 & SAE F-7 Medium density felts similar to SAE F-5 and recommended for similar applications, but where slightly less durable material is permissible. These felts are commonly used for: Grease retainers, Spacer strip seals, Weather stripping, Dust shields, and noise reduction linings.