KA040AR0 Inch Thin Section Angular Contact Ball Bearing – 101.6 × 114.3 × 6.35 mm
KA040AR0 thin section bearing reference: LYDL-A040 Type A, open angular contact.
Nominal d × D × B: 4 × 4.5 × 0.25 in (101.6 × 114.3 × 6.35 mm).
Four-inch angular contact support: check the shaft before selecting the bearing.
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 angular contact support: check the shaft before selecting the bearing
The KA040AR0 thin section bearing reference is an open Type A angular-contact design measuring 101.6 × 114.3 × 6.35 mm. Its four-inch bore is often confused with a 100 mm metric seat. That distinction matters before any load comparison: a nominal 100 mm shaft leaves a 1.6 mm diametral difference, which is not an installation clearance specification. LYDL quotations use the complete reference and an agreed mounting drawing. Dimensions · Load ratings · Brand names · Model FAQ
LYDL open Type A family reference photo used for the KA040AR0 size presentation; this is not a verified photograph of an individual KA040AR0 unit.
Resolve the 100 mm versus 101.6 mm interface
Start with the measured shaft and the housing drawing, including the bearing seats rather than the through-hole alone. Converting a metric assembly to this inch size can affect shoulders, locknuts and seal carriers. An adapter is a separate design decision; it must preserve support, concentricity and axial retention. Never treat the nominal size difference as a recommended loose fit.
For a four-inch shaft, the quarter-inch section keeps the reference outer envelope at 4.5 inches. The compact envelope does not remove the need for a rigid seat. State whether the inner or outer ring rotates and which component reacts the axial force. A single Type A bearing carries thrust in one direction; the complete support arrangement must react reverse thrust elsewhere.
Kaydon KA040AR0 reference load ratings
Kaydon reference rating
lbf
kN (converted)
Dynamic radial — Kaydon method
595
2.647
Dynamic radial — ISO comparison
1,353
6.018
Dynamic thrust
1,470
6.539
Static radial
1,490
6.628
Static thrust
4,300
19.127
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-A040 Type A
Inquiry identity for KA040AR0; supply specification requires confirmation.
KAYDON
KA040AR0
Official open Type A model with dimensions and loads listed above.
INA / Schaeffler
CSEA 040
Same nominal angular-contact envelope in catalog 575; configuration must be checked.
NSK
NBA10106
NBA angular-contact catalog entry for the nominal envelope; tolerances and internals may differ.
SKF
Kaydon KA040AR0 within SKF range
SKF/Kaydon naming context, not a separately verified interchangeable SKF design.
Kaydon uses A for angular contact in KA040AR0; 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.
Drawing review for an inch-based rotary module
A rotary inspection module with an existing inch shaft is a useful selection scenario. First check its axial force direction during motion, stopping and manual handling. A payload that sits above the bearing plane can also produce an overturning moment. Describe that offset rather than converting it into an unsupported single axial force. An opposed bearing arrangement may be appropriate, but its spacing and preload need calculation. This is an application assessment, not evidence of a completed LYDL installation.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)
KA040AR0
4
4.5
0.25
KA030AR0
3
3.5
0.25
KA050AR0
5
5.5
0.25
KB040AR0
4
4.625
0.3125
KA030AR0 and KA050AR0 retain the KA section but change both seating diameters. KB040AR0 keeps the four-inch bore while increasing the outside diameter to 117.475 mm and width to 7.9375 mm. Select between them from the available envelope and load case, rather than the shared 040 bore code alone.
Related model details: KA030AR0, KA050AR0, KB040AR0.
Browse the inch Type A size overview or the open angular-contact category. For the same nominal envelope with radial contact, review KA040CP0; changing contact type requires an arrangement review.
Check retention on both sides of the seat
Show the shoulder, retaining ring or locknut in section. Assembly force should act through the ring being fitted instead of through the balls. After the shaft and housing are assembled, inspect rotation and axial behavior using the agreed test method. Free rotation of an unpacked bearing cannot establish the mounted preload or runout. If two bearings are required, request a defined matched arrangement; ordering two AR0 references does not by itself specify a matched pair.
Supply identification, inspection and protection
For a retrofit inquiry, include the existing part label and photographs of the mating seats. Ask the quotation to identify the inspection dimensions, measurement conditions and documentation supplied. Individual protection should keep the open raceway clean during storage. The reference family photograph below is illustrative and cannot establish the cage, finish or inspection history of a shipped unit.Illustrative inspection and packing scenes, not an order-specific test report.
KA040AR0 selection questions
Can KA040AR0 be installed directly on a 100 mm shaft?
Its nominal bore is 101.6 mm, so a 100 mm shaft is not the matching nominal seat. Review the actual tolerances and any proposed adapter with the assembly designer before ordering.
Does AR0 specify a duplex pair for my four-inch spindle?
No. The reference is a single open angular-contact bearing. Pair arrangement, matching and preload must be specified separately; two individual units are not automatically a factory-matched set.
Is INA CSEA 040 a guaranteed replacement?
The cited INA table lists the same nominal 101.6 × 114.3 × 6.35 mm envelope in an angular-contact family. Check contact geometry, tolerances, cage, preload and mounting requirements before interchange.
Why does NSK call the comparable size NBA10106?
NSK uses NBA for its angular-contact thin-section family. NBA10106 is listed at 101.6 mm bore and 6.35 mm width; the short numeric code does not replace the catalog dimensions.
What should accompany a KA040AR0 replacement request?
Provide the existing drawing, quantity, axial load direction and whether a second bearing is retained. Include shaft and housing measurements if the machine documentation uses a rounded 100 mm description.
Request your KA040AR0 drawing and quotation
Identify the inquiry as LYDL-A040 Type A, KA040AR0 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.
