SKF7210CTCC78GPrecision Angular Contact Ball Bearing 50x90x20 mm, ISO P5 / ABEC 5, Special Internal Specification, Open

Product Description

What this part is

An SKF precision angular contact ball bearing in the 7210 envelope, 50 mm bore x 90 mm outside diameter x 20 mm wide. The outer ring is counterbored on one side so the full ball complement can be loaded and so the bearing develops a contact angle: it carries radial load plus thrust in one direction, and the high shoulder must face the thrust.

Decoding the designation

7210 – single-row angular contact ball bearing, 50 x 90 x 20 mm.
TC – SKF precision-series designation from the US precision range (the MRC lineage that SKF absorbed).
C78 – SKF special internal specification code: the bearing was built to a customer or OEM drawing rather than the plain catalogue standard. Because the content of a C-number specification is not published, the code is carried here as a searchable reference rather than expanded into individual specs.
G – supplementary SKF suffix on this build, retained as a searchable reference.
P5 – ISO tolerance class 5, comparable to ABEC 5.

What these specs mean in practice

P5 / ABEC 5 tightens bore, outside diameter, width and running accuracy well beyond a standard bearing, without the cost of P4. It is the grade used for precision drive spindles, indexing and rotary axes, gear-quality shafting and pump and compressor spindles — positions where repeatable location matters but the machine is not running at super-precision speeds. If your drawing calls for P4 or ABEC 7, this bearing is a class short even though the envelope is identical.

The C78 special-specification code is the part worth understanding before you substitute. Bearings built to a C-number typically differ from catalogue standard in internal clearance, preload, raceway geometry or cage, which means a plain catalogue 7210 will fit the same bore and housing but may not behave identically in a spindle that was designed around the special. Where the machine is not sensitive to that, a standard precision 7210 may be used.

Published dimensions

Bore (d): 50 mm
Outside diameter (D): 90 mm
Width (B): 20 mm
Rows: 1
Rolling elements: balls
Precision: ISO P5 / ABEC 5
Closure: open, no seals or shields
Outer ring: counterbored one side

Quantity and configuration

Sold as one bearing — inner ring, outer ring, ball complement and cage as one complete unit. This designation carries no universal-grinding or duplex suffix, so it is not a matched set and two clamped together will not develop a defined preload.

Fitting notes

Orient the counterbored (low shoulder) side away from the thrust load — fitted backwards the balls climb the raceway shoulder and the bearing fails quickly. Press or induction-heat onto the shaft against the inner ring only, and press into the housing against the outer ring only; never route mounting force through the balls. A single angular contact bearing locates the shaft in one direction only and needs an opposing bearing in the arrangement. The bearing is open, so it depends entirely on the housing for sealing.

Part number forms and nearby parts

Other 50 x 90 x 20 mm angular contact bearings share the same shaft and housing fit but differ in contact angle, precision class or special specification: SKF 7210 BEP and 7210 BECBP (B / BE = 40°), SKF 7210 ACD/P4A (AC = 25°), SKF 7210 CD/P4A (CD = 15°), NSK 7210CTYNP5 at 15° and 7210A5TYNP5 at 25°, FAG 7210-B-TVP-P5 at 40°, NTN 7210CP5 at 15°, Fafnir/Timken 2MM210WICR at 15° and 3MM210WICR at 25°, and MRC 7210 in the legacy US range. None of these carries the C78 special specification, and MRC’s 7000-series geometry (29°) differs from the ISO scheme, so check the contact angle your machine was designed around before substituting. SKF absorbed MRC, so MRC 7210 numbers are part of this lineage.