FAGB7218C.TPA.P4S.ULSuper Precision Spindle Bearing – Straight Bore, 90 mm ID, 160 mm OD, 30 mm Width, Open, 15° Contact Angle, P4S, Universal Light Preload, Phenolic Cage.

Product Description

What this part is:

FAG B7218-C-TPA-P4S-UL super-precision spindle bearing, a single-row angular contact ball bearing in the B72 heavy spindle series. Bore: 90 mm. Outside diameter: 160 mm. Width: 30 mm. Contact angle: 15°. Precision class: P4S. Open on both faces. Weight: 4.75 lb.

Decoding the designation:

B72: spindle bearing series with large-diameter balls. C: 15° contact angle. TPA: machined fabric-base laminate phenolic window cage. P4S: super-precision tolerance class with matched dimensional grading. UL: universal light preload, so any two bearings of this designation form a correct set in back-to-back, face-to-face or tandem arrangement. K5 appears on the carton as a supplementary FAG order code.

What these specs mean in practice:

Dynamic load rating: 125 kN (28,100 lbf). Static load rating: 75 kN (16,860 lbf). Limiting speed: 14,000 rpm. Maximum operating temperature: 100 °C. A 15° contact angle carries less thrust and runs faster than a 25° execution of the same envelope, which is why it is the standard machine-tool spindle choice. The phenolic cage is roughly a fifth the mass of brass, so it loads the ball set less at speed and holds oil in its own surface.

Quantity and configuration:

One bearing, in the universal light-preload execution. The ground ring faces set the preload as soon as the rings are clamped, with no spacer grinding, and a second bearing of the same designation completes a matched set.

Fitting notes:

Shaft seat to h5 and housing bore to H6 or closer hold the P4S running accuracy. Clamping is applied evenly across the ring faces so the ground offsets establish the preload.

Interchange guidance:

Same-specification 15° light-preload executions: SKF 7218 CD/P4ADGA, NSK 7218CTRDULP4, Fafnir 2MM218WI-CR-DUL, RHP 7218CTDULP4. Related size: B7218-E-T-P4S-UL (25° contact angle, same envelope, higher thrust capacity and lower speed). Punctuation variants: B7218C.TPA.P4S.UL, B7218-C-TPA-P4S-UL, B 7218 C TPA P4 UL, B7218CTPAP4K5UL.