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Brinelling (False) False brinelling is characterized by surface marks or blemishes on balls, rollers, or raceways that normally have a polished or satin finish appearance. This is usually caused by continuous non-rotational vibrations and is shown in Figure 303. (Refer to Table 302 and Table 303 for limits.)
Cracks Cracks are separations, fissures, or ruptures characterized by sharp edges and/or sharp changes in direction. Cracks are cause for rejection on functional or non-functional surfaces.
Corrosion Corrosion on surface areas is characterized by a broken, pitted, or discolored appearance. Corroded surface areas will exhibit an orange peel appearance. Figure 304 shows corrosion. (Refer to Table 302 and Table 303 for limits.)
Burnishing Burnishing is a mechanical smoothing of a surface, sometimes resulting in discoloration around the contact area. This is not accompanied by wear. Acceptable components show wear of less than 0.000050 inch. (See roller end wear and cage defects sections.)
Dents Dents are slight depressions or hollows on the surface made by mechanical injury to the material such as blows or pressure caused by hard objects contacting the finished surface. They are usually bright bottomed and irregular in shapes. (Refer to Table 303 for limits.)
Fretting corrosion Fretting corrosion is rapid oxidation of surfaces of closely fitted parts. It is characterized by rusty appearing surfaces ranging from black (well bonded) to a fairly bright reddish brown (often loosely bonded or even free particles). Fretting corrosion is acceptable on non-functional surfaces if less than 30 percent of the surface area is affected and there is no dimensional change. (See Figure 305.)
Heat discoloration Heat discoloration of bearing surfaces ranges from light straw to blue or purple. Purple or blue discoloration that still exists after the bearing is cleaned will be cause for rejection.
Stains Stains are surface discoloration’s, which range from black to dark reddish-brown in color. Surface areas which are stained will exhibit an
intact, non-pitted, unbroken appearances. Stains are acceptable on all surfaces.
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Inspection
20-00-02/70-00-01
Table 301. Bearing Component Inspection Criteria Definitions and Limits (Cont)
Term Definition (Description of Defect)
Varnishing Varnishing is the breakdown of a lubricant because of temperature which results in a harmless surface discoloration which can be
recognized by its light brown to black appearance. Varnishing is acceptable on all surfaces.
Galling Galling is a more severe condition of fretting corrosion where there is a significant transfer of material between surfaces due to welding and break-away of particles. It is caused by excessive sliding between two poorly lubricated surfaces which are forced into contact with each other by high pressure. (Refer to Table 304 and Table 305 for limits.)
Rust See Corrosion.
Pits Pits are small, irregular shaped cavities in a surface from which material has been removed by corrosive action such as chemical or electrolytic attack. (Refer to Table 302 and Table 303 for limits.)
Nicks See Dents.
Surface slag inclusions Surfaces slag inclusions are foreign materials, embedded in the metal. These occasionally appear as dark spots or lines following bearing operation. (Refer to Table 304 and Table 305 for limits.)
Scratches and scuffs Scratches and scuffs are narrow, shallow linear abrasions caused by movement of sharp objects or particles across a surface. These penetrate the original surface of bearing components. (Refer to Table 302, Table 303, Table 304, and Table 305 for limits.)
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