The purpose of a sleeve bearing is to initiate linear movement. In addition to this, it can help aide vibration and noise reduction by absorbing friction. Sleeve bearings
are usually made from stainless steel, but you can also get bronze and steel. In some cases, you'll find brass and plastic sleeve bearing as well, but they are for specific applications. Constant lubrication
is necessary for bronze type sleeves. By doing so, it prevents premature breakdown.
There are two sleeve bearing designs - flanged and cylindrical. The latter generally has a straight exterior and flush inside. Flanger, on the other hand, has a flange.