The Timken Company 45187S Oil Seal

The Timken National Oil Seal 45187S is a single-lip nitrile seal designed to retain lubricants and keep contaminants out of rotating shaft systems, making it a common choice for industrial gearboxes, pumps, electric motors, conveyors, and heavy-duty vehicle axles operating in demanding environments. This Timken National (National brand) oil seal carries MPN 45187S and features a solid construction with a 4.000 in shaft diameter, a 4.876 in housing bore, and an outside diameter of 4.881 in, with an overall width of 0.250 in. It is a Seal Type: Single Lip Without Spring, Design Type 4S, and made from Nitrile (NBR). Maximum shaft surface speed is 2000 ft/min, with a misalignment tolerance of 0.005 in, and it is rated for continuous operation from -40°F to 225°F (-40°C to 107°C). Typical applications are general purpose in rotating equipment where lubricant retention and contaminant exclusion are essential, including industrial gearboxes, pumps, conveyor systems, and general power transmission equipment, helping protect bearings and shafts from dirt, moisture, and lubricant leakage. Common replacements include SKF equivalent oil seals, CR (Chicago Rawhide) equivalents, and National 4S Series oil seals.