Oil seals are commonly used to keep fluid from within a bearing from leaking through the space between the shaft and the housing, as well as preventing any corrosive materials or debris such as dirt, water and grime getting in through the clearance. Their main use is protecting the ball bearing inside. See our full range of metric, imperial and cap ends from Online Bearings and find the right oil seal for you. If you can't find the product you want, then contact us online for a call back at your convenience.