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Precision Thin Section Bearings are Special
The Silverthin Series are manufactured to industry standard sizes. The bearing widths and sections(distance from bore to outside diameter) in each series remains constant regardless of the change in bore diameter. (More information about thin section bearings)

Due to the large diameters and thin sections of these bearing products, it is necessary to address measurement and inspection techniques. To accurately measure the bore and outside diameters of thin section bearings, a specific procedure must be followed.

Appropriate measuring equipment must be used which will allow the inspector to take 3 to 5 readings around the circumference which are then averaged to determine the true measurement of the bearing in the free state (unmounted). This procedure allows for the inherent out-of-roundness these bearings will exhibit.

When measuring these bearings, special care must be exercised to ensure neither the bearing weight or pressure from the measuring equipment affects the measurements.

If thin section bearings are being installed into a housing, pressure should be applied only on the outer ring. Bearings to be installed on a shaft should be pushed on the inner ring. Since the majority of Silverthin bearings are open (without seals), a clean, contaminant-free installation area is advised.

Rolling element anti-friction bearings rely on ball and raceway surface lubrication. A thin film of oil or grease should be used. Be sure not to contaminate the lubricant used in the bearings. Our standard open (unsealed) bearings are shipped with only a light oil as a corrosion inhibitor. You must lubricate these bearings with the appropriate grease or oil for your application. Sealed bearings are shipped as standard practice with 20% - 30%  fill of Mil-G-81322 grease.

Load Ratings
Information listed in this catalog such as load ratings and bearing dimensional data has been compiled from industry standard data as well as ABMA and ANSI information and formulas. Technical information and ratings have been modified from empirical data and test data from Silverthin.TM Load capacities show in the catalog are not additive. For combined radial and axial loading an equivalent radial loading must be calculated.

Housing & Shaft Fits
Thin section bearings are affected by the tolerance, roundness, and expansion & contraction rates of the housing & shafts used to mount these bearings. The "Precision toler-ances & Recommended Fits" shown in this catalog are for bearings with standard diametral clearance and steel shafts & housings. Bearings with special clearances or preloads and those which are mounted in, or have shafts in, materials other than steel, will need special internal clear-ance consideration to account for different expansion & contraction rates of dissimilar materials.

Thin Dense Chrome Plating
NTDC nodular thin dense chrome plated bearing rings of 52100 steel are designated with an “A” in the Silverthin part numbering system. This electro-deposited chrome plat-ing process will not chip, crack or peel under severe stress experi-enced in bearing raceways. This process increases bearing corrosion resistance, improves surface hard-ness to the Rc70-Rc78 range which in turn reduces bearing friction and helps retain lubrication.

We apply this plating to our standard 52100 steel inner and outer rings so allowances must be made to standard housing and shaft fits to allow for the plating build up on the exposed surfaces, especially the bore and outside diameter. The plating build up per surface can generally be from .000040 inch to .00015 inch. Contact Silverthin Bearing for bore and shaft fits.

Silverthin™ Specifications

Races (rings)
AISI 52100 vacuum degassed bearing steel Please check with factory for operating temperatures for sealed bearings
Heat treatment
Through hardened and stabilized for use at -65 degrees F to +250 degrees F.
AISI 52100, 440C or ceramic (Silicone Nitride)
Buna-N rubber-metal reinforced
"A" type - circular pocket G,H, R,U,& F "C" & "X" type -snapover type D, N, P, L, T & F
Diametral Clearance
ABMA standard 26.2
ABMA standard 26.2
Internal geometry
ABMA standard 26.2
All SilverthinTM bearings are marked with part number, lot code and "Silver" on the outside diameter
Immersion and agitation with preservative oil applied.
Sealed in plastic and boxed up to 12" bore. Boxing or special packaging as required.
Operating Groups of Mechatronics Inc.including Silverthin Bearing Group, are registered to the ISO 9001:2000 quality standard. A copy of the registration certificate is available upon request.
Sealed bearings 20% - 30% fill of Mil-G-81322 grease Open bearings are dipped in light oil as a corrosion inhibitor (not intended to be a bearing lubricant)
Silverthin Bearing Group of Mechatronics, Inc.
Toll Free 866.294.5841 • Fax 425.222.7535 • email
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