Description: 3-bolt flange units are round bearing housing units featuring 3 bolt holes, for added security compared to a 2-bolt housing unit; They can be used in applications where more space is provided for mounting the housing unit. Flange housing units are used when the bearing mounting surface is perpendicular to the shaft axis. Normally these bearings can be adjusted or aligned within the housing to accommodate long shafts. For most manufacturers, flange units are available in two series: inch dimensions and metric dimensions. Flange unit materials include cast iron, thermoplastic, glass filled PBT polyester, stainless steel, and other metals.Plastic housing units avoid rust and corrosion, requiring minimal to no maintenance, however they may not be suitable in high temperature applications.In addition to material variations, housing units may include a grease fitting for adding lubricant or slingers on the sides for dust protection. Flange housing units are either set screw locking type, sleeve collar, or eccentric locking collar locking type for one directional applications. A multitude of bearing inserts with varied materials and seal types are available with these housing units. Chrome steel bearings are regreaseable and often paired with cast iron units. UHMW-PE bearings are designed for applications in wet or harsh environments, are self-lubricating, and can be used with most metal housings. Bronze bearings are preferred for lighter applications and continuous lubrication. Stainless steel, nickel, and plated zinc are also available, depending on the manufacturer. Inner ring width can impact bearing performance; narrow inner rings are more suitable for light duty applications. MRO Supply offers a wide range of 3-bolt flanged housing units from various brands, sizes, materials, and bearing types to suit a multitude of applications.