Below is a list of Pillow Block Bearings manufacturers from Waltham, Massachusetts. Pillow block bearings are mounted units that provide low friction support for shafts moving parallel to the mounting surface and passing through the unit’s center. Also called a plumber’s block, these bearings allow the shaft to smoothly glide in and out of the casing with little friction, resistance or heat. They are basically a ball bearing inserted into a mountable enclosure.