Description
Authorized Channel Procurement — Every INA NKS55-XL needle roller bearing we ship is backed by traceable distributor documentation confirming origin and batch lineage.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | INA NKS55-XL |
| Bearing Type | Needle Roller Bearing with Machined Outer Ring |
| Bore Diameter (Fw) | 55 mm |
| Outside Diameter (D) | 72 mm |
| Width (B) | 22 mm |
| Seal or Shield Type | Open |
| Number of Rows | Single Row |
| Arrangement | Without Inner Ring |
| Material | Bearing Steel |
| Weight | 0.27 kg |
| Load Direction | Radial |
The XL suffix on this designation is flagged as unverified and should be confirmed against the current INA catalog before final specification lock-in.
Application Suitability
| Industry | Typical Applications |
|---|---|
| Material Handling | Conveyor drive gearbox needle stages, transfer cart wheel hubs |
| Industrial Machinery | Packaging machine pivot arms, textile loom rocker shafts |
| Electric Motors | Auxiliary shaft supports in large-frame induction motors |
| Automotive Repair | Steering column intermediate shafts, transmission laygear supports |
| General MRO | Replacement radial supports in legacy OEM equipment with compact envelope constraints |
What Happens When a Needle Bearing Cross-Reference Ignores the Outer Ring Profile
A dimensionally correct substitution with the wrong outer ring geometry will bind or walk under radial load within weeks.
I have seen procurement teams match the 55 mm bore and 72 mm OD on paper, then install a drawn-cup HK series where the application required a machined outer ring NKS type. The thin-walled drawn cup deformed under cyclic radial loading on a conveyor drive, walked out of the housing bore, and took the entire line down for an unplanned shift. Cross-referencing needle bearings is not just about bore and OD — the outer ring construction, cage guidance method, and load path geometry all have to align with the actual duty cycle [NEED_CITE: needle roller bearing failure modes and classification per ISO 15243].
Matching Compact Radial Envelopes to Real Load Spectra
The INA NKS55-XL needle roller bearing delivers high radial load capacity within a 55×72×22 mm cross-section that most ball or roller bearings simply cannot match. In material handling gearboxes where shaft spacing is fixed and housing bores are already machined, this compact profile is often the only viable replacement. We routinely help buyers confirm whether the machined outer ring of the NKS series is the correct fit versus a drawn-cup or inner-ring-equipped alternative, especially when the application involves shock loads from start-stop cycling on conveyor systems.
Radial Loads, Shaft Speed, and the Open-Type Lubrication Decision
Radial loading dominates in needle roller applications, and the INA NKS55-XL is designed for exactly that — sustained radial force without significant axial component. Speed capability depends heavily on lubrication: open-type construction means the bearing relies entirely on external grease or oil supply, which gives maintenance teams flexibility to choose lubricant viscosity and re-greasing intervals matched to operating temperature and contamination levels. In dusty environments like aggregate handling or mining-adjacent conveyor systems, the absence of integrated seals shifts responsibility to the housing seal design, and that interface needs to be verified before installation [NEED_CITE: open-type bearing contamination ingress and L10 life reduction].
Decoding the Core Specs That Actually Matter
The machined outer ring on the NKS series provides a rigid, precision-ground raceway that maintains geometry under heavy radial load — unlike drawn-cup designs where the thin outer shell can ovalize in soft housings. The 55 mm roller complement bore (Fw) rides directly on the shaft or a hardened sleeve, which means shaft surface hardness and finish directly affect bearing life; a soft or rough shaft journal will wear prematurely regardless of bearing quality. Open-type construction eliminates seal friction but demands disciplined re-lubrication schedules, particularly in continuous-operation applications like motor shaft supports or packaging machine pivots where heat buildup accelerates grease degradation. The single-row arrangement keeps the axial footprint at 22 mm, which is critical when the housing envelope is constrained by adjacent components.
The Downtime Cost Nobody Budgets For
Installing a counterfeit or incorrectly cross-referenced needle bearing in a critical drive position does not just cause a bearing failure — it causes secondary damage to shafts, housings, and gear meshes that multiplies repair cost and lead time. A soft inner raceway on a fake needle bearing spalls under load, sending debris through the gearbox oil and scoring gear flanks. Incorrect outer ring geometry causes housing bore wear, turning a simple bearing swap into a line-bore or housing replacement project. The ISO 281 life calculation framework assumes correct selection and genuine components; deviations from either invalidate the L10 estimate entirely [NEED_CITE: ISO 281 bearing life calculation assumptions and limitations].
How We Keep Your Needle Bearing Inventory Honest
Every INA NKS55-XL needle roller bearing we source flows through authorized distributor channels with full batch traceability, so you know exactly which production lot is in your hands. Our cross-reference database matches not just bore and OD but outer ring construction, cage type, and load ratings across INA, SKF, NTN, and other major brands — preventing the geometry mismatches that cause field failures. For buyers importing into regions with strict origin documentation requirements, we provide country-of-origin certificates and HS code support with every shipment. When authenticity questions arise, we guide you through INA’s official QR code verification pathway so you can confirm the bearing yourself before it touches a shaft. We also supply dimensional inspection reports on request, giving your receiving team independent confirmation of Fw, D, and B tolerances before the bearing leaves quarantine.
Documentation & Authenticity
- Supplier Certificate of Conformity referencing batch and lot numbers specific to your INA NKS55-XL shipment
- INA official app QR code verification walkthrough for confirming authenticity at your receiving dock
- Country-of-origin documentation prepared for import compliance in Middle East, African, and Latin American customs jurisdictions
- Third-party dimensional inspection report verifying Fw 55 mm, D 72 mm, and B 22 mm tolerances before dispatch
- Material certificate confirming bearing steel composition for your quality management records
Storage, Handling & Mounting
- Keep the INA NKS55-XL in its original sealed packaging until the moment of installation — the open-type design exposes roller surfaces to ambient moisture and particulate immediately upon unwrapping
- Store in a climate-controlled environment with stable temperature to prevent condensation inside the packaging, which is especially damaging to the unsealed raceways of this needle roller bearing
- Wear clean lint-free gloves when handling the 55 mm bore surface; fingerprint acids on the bare bearing steel can initiate corrosion pits that propagate under radial load
- Verify shaft journal hardness and surface finish before pressing the needle roller complement onto the shaft — the inner-ring-free design of the NKS series makes the shaft itself the inner raceway
- Confirm housing bore tolerances and surface finish for the 72 mm machined outer ring; an out-of-round housing will preload the rollers unevenly and truncate fatigue life
- Establish a re-lubrication schedule immediately after installation since the open-type construction provides no factory-fill grease retention
Request a Specification Package Before You Commit
Share your operating parameters — radial load magnitude, shaft speed, ambient temperature, and housing seal configuration — so we can confirm the INA NKS55-XL is the correct selection for your application or recommend a sealed or alternate-clearance variant. If you are replacing an existing bearing by OEM equipment number, send us the nameplate data and we will cross-reference against our interchange database to verify dimensional and performance compatibility. Request the documentation package including origin certificates and inspection reports upfront so your procurement and quality teams can approve the source before the order ships.
Frequently Asked Questions
Q: How can I verify that my INA NKS55-XL is genuine and not a counterfeit?
A: Every genuine INA bearing carries a unique QR code that links to the manufacturer’s official verification system. We provide a step-by-step verification walkthrough so your receiving team can scan and confirm authenticity before the bearing enters your inventory. Batch traceability documentation accompanies each shipment, linking your specific bearing to its production lot and distributor chain.
Q: What is the difference between NK, NKS, and RNA needle roller bearing types?
A: The NK series uses a drawn-cup outer ring suited for lighter loads and simpler housings. The NKS series features a machined outer ring for higher radial loads and more demanding applications where housing rigidity is critical. RNA types are needle roller bearings without any inner ring, designed to run directly on a hardened shaft journal. Selection depends on load magnitude, housing bore precision, and whether the shaft can serve as the inner raceway.
Q: What should I check when cross-referencing this bearing to another brand?
A: Beyond matching the 55 mm bore, 72 mm OD, and 22 mm width, you must verify outer ring construction type, cage material and guidance method, dynamic and static load ratings, and any suffix designations that affect performance. A base-number match alone can result in premature failure if the internal geometry or load capacity differs. Our cross-reference database aligns all of these parameters across major brands.
Q: How should I lubricate an open-type needle roller bearing like the NKS55-XL in continuous operation?
A: Open-type bearings require external lubrication through the housing or shaft. Grease selection should account for operating temperature, speed, and contamination exposure. In continuous-duty applications such as conveyor drives or motor supports, establish re-lubrication intervals based on thermal conditions and replenish before grease degradation accelerates wear on the needle roller complement.
Q: Can I get import documentation for customs clearance with this bearing?
A: We provide country-of-origin certificates, HS code classifications, and commercial documentation formatted for import compliance across Middle East, African, Latin American, and Central Asian jurisdictions. Let us know your destination country and any specific certificate requirements at the inquiry stage so we prepare the package before shipment.
Secure Your INA NKS55-XL Specification Review Today
Send us your application parameters or OEM equipment number, and we will return a verified cross-reference with full documentation package within one business cycle. Contact our technical sourcing team through your established inquiry channel to initiate the selection review.
