Oil seals and radial shaft seals

In most assemblies the oil seal costs the least and decides how long everything else lasts. Once dust or water reaches the housing, even a high-quality bearing can fail within weeks.

You order a radial shaft seal by three dimensions, always given in the same order: shaft diameter, housing bore diameter and height. A 50 x 72 x 8, for example, fits a 50 shaft in a 72 bore and is 8 millimeters high. Our catalog lists all three dimensions for most of its seals, so you can search by size when you have no part number.

Next comes the design type: with or without a garter spring, with or without an extra dust lip, and with a metal or rubber outer case. Most failed replacements come down to this—the size is right, the design is not, and two months later the seal is leaking again.

Split pillow block housings follow a sealing logic of their own. A single SNL housing can take felt seals, labyrinth seals, V-rings or double-lip seals, and the right one depends on the surroundings: felt for a clean shop, labyrinth where fine dust is present, double lip where equipment is washed with pressurized water. Few decisions affect bearing life more, yet it is rarely considered at the time of purchase.

To request a quote, the size is enough, or the old seal in hand so it can be measured—no part number needed.