KB050AR0 Inch Thin Section Angular Contact Ball Bearing – 127 × 142.875 × 7.9375 mm
KB050AR0 thin section bearing reference: LYDL-B050 Type A, open angular contact.
Nominal d × D × B: 5 × 5.625 × 0.3125 in (127 × 142.875 × 7.9375 mm).
Five-inch KB selection: verify the catalog identity before a replacement order.
Single-bearing thrust support is directional; pairing and preload are separate specifications.
Kaydon reference loads are shown with attribution; LYDL supply capacities require confirmation.
Request the proposed drawing and quotation with quantity and application details.
Five-inch KB selection: verify the catalog identity before a replacement order
The KB050AR0 thin section bearing reference describes a 127 × 142.875 × 7.9375 mm open angular-contact envelope. A replacement inquiry for this size needs more than a plausible cross-reference number: the complete designation, catalog dimensions and supplied configuration must agree. This page distinguishes verified Kaydon and NSK entries from an INA exact-size designation that has not been confirmed in the cited official table. Dimensions · Load ratings · Brand names · Model FAQ
LYDL open Type A family reference photo used for the KB050AR0 size presentation; this is not a verified photograph of an individual KB050AR0 unit.
Treat an incomplete cross-reference as an open question
The Schaeffler catalog establishes CSEB as an angular-contact section family, but its cited size table does not confirm a CSEB 050 entry. A neighboring size or predictable numbering pattern is insufficient evidence for an exact replacement. Send an existing INA label or manufacturer drawing if that is the part being replaced; LYDL can then review the actual interfaces and configuration rather than an assumed code.
For the verified KB050AR0 envelope, distinguish the nominal five-inch bore from the required shaft fit. The outer seat is 5.625 inches, and the axial width is 0.3125 inch. Confirm that neither a five-and-a-half-inch housing prepared for KA050 nor a three-eighths-inch spacer stack is being reused without revision.
Kaydon KB050AR0 reference load ratings
Kaydon reference rating
lbf
kN (converted)
Dynamic radial — Kaydon method
976
4.341
Dynamic radial — ISO comparison
2,081
9.257
Dynamic thrust
2,410
10.720
Static radial
2,500
11.121
Static thrust
7,210
32.072
These figures are Kaydon catalog reference capacities, not verified LYDL supply ratings. Dynamic ratings use a one-million-revolution L10 basis; the radial ISO comparison follows ISO 281:1990. Static values assume rigid supporting members. Do not add these ratings, treat them as simultaneous permissible loads or double them to rate a pair. Conversion: 1 lbf = 0.0044482216152605 kN; displayed values are rounded.
KAYDON, INA, NSK and SKF naming comparison
Brand
Reference or naming context
What is established
LYDL
LYDL-B050 Type A
Inquiry identity for KB050AR0; supply specification requires confirmation.
KAYDON
KB050AR0
Official open Type A model with dimensions and loads listed above.
INA / Schaeffler
CSEB family — exact size unconfirmed
CSEB angular-contact family confirmed; exact five-inch entry not established by the cited official table.
NSK
NBA12707
NBA angular-contact catalog entry for the nominal envelope; tolerances and internals may differ.
SKF
Kaydon KB050AR0 within SKF range
SKF/Kaydon naming context, not a separately verified interchangeable SKF design.
Kaydon uses A for angular contact in KB050AR0; R identifies a circular-pocket ring cage code, and the final 0 is a separate reference precision code. It is not an LYDL ISO P0 claim. INA uses the CSE angular-contact family, while NSK uses NBA. NSK nominal widths may be rounded in its metric table. SKF/Kaydon documentation also shows the KDN. brand-prefix format; the complete order designation and suffixes require confirmation. Equal nominal dimensions do not prove identical contact geometry, preload, cage, tolerances or life. Brand references do not imply authorization or current availability.
Procurement review for a legacy five-inch assembly
Legacy drawings sometimes mix supplier numbers, inch dimensions and rounded metric descriptions. Preserve the original designation in the inquiry and list measured interfaces separately. Record whether the old unit was one bearing, a marked pair or a cartridge containing additional support. Photographs can help identify labeling and orientation, but they cannot establish hidden raceway geometry or internal preload. A replacement recommendation should resolve those gaps before supply.General application examples; suitability and performance require review of the actual machine.
Compare related Type A mounting envelopes
Reference
Bore d (in)
Outside D (in)
Width B (in)
KB050AR0
5
5.625
0.3125
KA050AR0
5
5.5
0.25
KC050AR0
5
5.75
0.375
KB060AR0
6
6.625
0.3125
KA050AR0 uses the same bore with a smaller 139.7 mm outer diameter. KC050AR0 increases the outer diameter to 146.05 mm and the width to 9.525 mm. KB060AR0 retains this section while moving to a six-inch shaft interface; that is a bore change rather than a direct replacement.
Related model details: KA050AR0, KC050AR0, KB060AR0.
Browse the inch Type A size overview or the open angular-contact category. For the same nominal envelope with radial contact, review KB050CP0; changing contact type requires an arrangement review.
Keep reverse-thrust requirements visible in the purchase drawing
An angular-contact bearing may appear externally similar to a radial-contact unit of the same envelope. Show the operating thrust arrow and the opposing reaction in the assembly drawing. If the load reverses, specify how the second support participates. Changing from Type C or Type X to this Type A reference requires an arrangement review; nominal dimension agreement alone does not preserve the original load path.
Supply identification, inspection and protection
For spare-parts control, request labels that include the complete LYDL supply identity, reference model and drawing revision. If an inspection certificate is needed, define its scope in the quotation. Do not use the absence of a verified INA cross-reference as a reason to omit incoming dimensional checks or substitute an unsupported universal-equivalence statement.Illustrative inspection and packing scenes, not an order-specific test report.
KB050AR0 selection questions
Why is no exact INA replacement asserted for KB050AR0?
The official CSEB table cited here does not establish the five-inch entry. An exact model should be confirmed from a manufacturer drawing or another official listing before it is presented as a verified reference.
Is NSK NBA12707 documented at this size?
Yes. NSK catalog 1153 lists NBA12707 at 127 × 142.875 × 7.938 mm. The width is rounded in that table; matching nominal dimensions still does not establish identical internal configuration.
Will KB050AR0 fit a 139.7 mm outer seat?
Its nominal outside diameter is 142.875 mm. A 139.7 mm seat belongs to the smaller KA050 envelope and needs a redesign before this KB size can be considered.
Can a legacy CP0 number simply be changed to AR0?
No. That changes the contact arrangement from radial to angular contact. Review the axial force direction, opposing support and installation requirements, even when the nominal envelope matches.
What evidence helps identify an unmarked five-inch spare?
Provide precise bore, outside diameter and width measurements, clear views of any markings and the assembly section. Those details support identification, but hidden geometry and preload may still require manufacturer confirmation.
Request your KB050AR0 drawing and quotation
Identify the inquiry as LYDL-B050 Type A, KB050AR0 reference. Send quantity, destination and the available assembly drawing. Specify single-bearing or matched-set requirements, load directions and any acceptance documentation needed. LYDL supply loads, contact geometry, accuracy, cage and delivery conditions must be confirmed for the quoted configuration.
