A needle roller bearing is a special type of roller bearing which uses long, thin cylindrical rollers resembling needles. Ordinary roller bearings' rollers are only slightly longer than their diameter, but needle bearings typically have rollers that are at least four times longer than their diameter. Like all bearings, they are used to reduce the friction of a rotating surface. Needle bearings have a greater surface area in contact with the races, so they can support a greater load. They are also thinner, so they require less clearance between the axle and the surrounding structure. Specifications Bore Diameter: 1.7500 In Outside Diameter: 2.2489 In Width: 1.7600 In Material: Chrome Steel Series: Mi Minimum Radius: 0.0600 In Lubrication Hole Type: Lubrication Hole Standards Met: Ms 500072-25 Compatible Bearing: Mr 36 Closure Type: Open Type Of Needle Bearing: Separable Inner Ring Only - Heavy Duty Needle Roller Bearing