Sizes & Types of Pillow Block Bearings

Pillow Block Bearings

If you’re in need of pillow block bearings, chances are you already know a thing or two about them. For those unfamiliar, we’ll use this post go through the basics: sizes, types, and selection.

When the mounted shaft is running parallel to the mounting surface, then a pillow block bearing is often used. The pillow block is typically made of cast iron or cast steel and the center line of its mounting holes run perpendicular to the mounting shaft.

Not to be confused with plummer blocks, which are designed for more high-capacity applications and in more corrosive environments, pillow blocks are used for light loads with low torque.

Types of Pillow Block Bearings

Pillow block housings are either split or solid. A split type bearing housing is made of two pieces which can be separated – for bearing replacement, cleaning, or lubrication – whereas a solid type (unsplit) housing is made from a single piece.

Pillow block bearings vary by the type of rolling element which might include ball bearings, roller bearings (which consist of cylinders between in the inner and outer rings of the bearing), tapered rollers, needle rollers; or metallic or synthetic bushing.

Certain combinations of housing type and bearing type determine the best pillow block bearing for a given application or condition.

Pillow Block Bearing Sizes

"Type E" Pillow BearingThe size of a mounted bearing needed for a given application depends primarily on the load and the diameter of the mounted shaft. For heavy-duty loads, here at MDS we offer the “Type E” pillow blocks – which are available in 2-bolt mounts or 4-bolt mounts – and standard pillow blocks for regular loads.

The bore diameters can range from 5/8” or ¾” pillow block bearings all the way to 5”.


Environment, load, and the size of the mounted shaft are the primary factors in selecting the right pillow bearing. In environments in which contaminants are a concern, a solid bearing housing with certain sealing arrangements might be the best choice. High-capacity loads or harsh environments might require a heavy-duty pillow block bearing or even a plummer block. For light loads, a standard pillow block with a bore size that matches up with the mounted shaft may suffice.

For a wide selection of pillow block bearings, browse our online inventory or contact MDS to find out more about our products.