Spherical roller bearings are inherently self-aligning and very robust. The two rows of rollers make the bearings able to carry heavy loads. Invented by SKF and refined over the years, the present SKF range of spherical roller bearings includes a wide range of sizes of several ISO Dimension Series and also includes special designs, for example, for vibrating screens and similar applications. More recently a range of sealed spherical roller bearings has been added to the assortment. Split spherical roller bearings are usually based on the standard bearings but can be customized as required.