KB040AR0 Inch Thin Section Angular Contact Ball Bearing – 101.6 × 117.475 × 7.9375 mm
KB040AR0 thin section bearing reference: LYDL-B040 Type A, open angular contact.
Nominal d × D × B: 4 × 4.625 × 0.3125 in (101.6 × 117.475 × 7.9375 mm).
Four-inch bore with a 5/16-inch section: evaluate the intermediate envelope.
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.
Four-inch bore with a 5/16-inch section: evaluate the intermediate envelope
The KB040AR0 thin section bearing reference has a 101.6 mm bore, 117.475 mm outside diameter and 7.9375 mm width. This open Type A design sits between the KA and KC section choices at the same four-inch bore. Its purpose in a selection comparison is to assess additional section and mounting space together, rather than treating the shared bore as proof of interchangeability. Dimensions · Load ratings · Brand names · Model FAQ
LYDL open Type A family reference photo used for the KB040AR0 size presentation; this is not a verified photograph of an individual KB040AR0 unit.
Translate the section increase into housing changes
Relative to KA040AR0, the KB envelope adds 3.175 mm to the outside diameter and 1.5875 mm to the width. Those changes can affect the housing wall, bolt clearance and locknut position. Check the whole cartridge drawing before proposing a section upgrade. A shared 101.6 mm bore preserves only one nominal interface; shoulder geometry and other mounting details still require confirmation.
Compare loads using a consistent calculation basis. Kaydon publishes two radial dynamic columns, so selecting the larger number from one series and the smaller from another produces a misleading comparison. This page keeps the Kaydon-method and ISO-comparison values separate and also identifies thrust and static ratings. None is automatically the allowable load of the surrounding assembly.
Kaydon KB040AR0 reference load ratings
Kaydon reference rating
lbf
kN (converted)
Dynamic radial — Kaydon method
865
3.848
Dynamic radial — ISO comparison
1,934
8.603
Dynamic thrust
2,100
9.341
Static radial
2,040
9.074
Static thrust
5,890
26.200
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-B040 Type A
Inquiry identity for KB040AR0; supply specification requires confirmation.
KAYDON
KB040AR0
Official open Type A model with dimensions and loads listed above.
INA / Schaeffler
CSEB 040
Same nominal angular-contact envelope in catalog 575; configuration must be checked.
NSK
NBA10107
NBA angular-contact catalog entry for the nominal envelope; tolerances and internals may differ.
SKF
Kaydon KB040AR0 within SKF range
SKF/Kaydon naming context, not a separately verified interchangeable SKF design.
Kaydon uses A for angular contact in KB040AR0; 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.
Section trade-off in a compact actuator support
An actuator output support may have a fixed four-inch shaft but some flexibility in the housing envelope. In that case, compare KA, KB and KC using the actual radial load, axial force direction and available axial length. Include acceleration and emergency stopping loads. A thicker section may be worth evaluating, but it does not eliminate the need for opposing thrust support or establish the final torsional and tilting stiffness.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)
KB040AR0
4
4.625
0.3125
KA040AR0
4
4.5
0.25
KC040AR0
4
4.75
0.375
KB050AR0
5
5.625
0.3125
KA040AR0 is the narrower four-inch option; KC040AR0 requires a larger 120.65 mm outer seat and 9.525 mm width. KB050AR0 retains the KB section while increasing the bore to five inches. Use these comparisons to separate a section change from a shaft-diameter change.
Related model details: KA040AR0, KC040AR0, KB050AR0.
Browse the inch Type A size overview or the open angular-contact category. For the same nominal envelope with radial contact, review KB040CP0; changing contact type requires an arrangement review.
Revisit the spacer stack after changing series
An existing spacer cut for a quarter-inch bearing should not be reused by assumption when moving to the 5/16-inch section. Recalculate retention and adjustment travel from the final drawing. Where matched bearings are involved, preserve their orientation and matching identity. Do not use the generic AR0 suffix to infer a particular factory preload, universal pairing capability or contact-angle specification for LYDL supply.
Supply identification, inspection and protection
Identify the selected KB section on both the purchase drawing and package label to prevent confusion with the visually similar KA040 reference. Ask for the dimensional and configuration checks needed at receiving. A useful inspection record names the measured characteristic and acceptance limit, rather than stating only that a bearing is ‘high precision’.Illustrative inspection and packing scenes, not an order-specific test report.
KB040AR0 selection questions
Why is KB040AR0 wider than KA040AR0 with the same bore?
The second series letter identifies a different section family. KB uses 0.3125 inch, whereas KA uses 0.25 inch, so both the outer diameter and width change.
Is NSK NBA10107 only 7 mm wide?
No. The NSK catalog lists 7.938 mm, a rounded presentation of the 5/16-inch width. Read the table dimensions rather than interpreting the abbreviated 07 as an exact width.
Which Kaydon dynamic radial value should be compared across sizes?
Use the same method column for every candidate and apply its stated calculation basis. The Kaydon-method value and the ISO comparison value should not be mixed in a ranking.
Does a KB section remove the need for reverse-thrust support?
No. The single-bearing Type A contact arrangement still supports thrust in one direction. Section size and support direction are different design decisions.
What must change in a KA040-to-KB040 retrofit drawing?
At minimum, review the 117.475 mm housing seat, 7.9375 mm axial width and retention stack. Confirm shoulders and the complete proposed supply geometry as well.
Request your KB040AR0 drawing and quotation
Identify the inquiry as LYDL-B040 Type A, KB040AR0 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.
