INA NKI40/30-TV-XL Needle Roller Bearing 40x55x30mm

Authorized Channel Traceability — Every INA NKI40/30-TV-XL needle roller bearing we ship carries batch-level documentation traceable back through authorized distributor channels, giving MRO buyers and importers verifiable proof of origin before the crate leaves the warehouse.

Technical Specifications

The XL suffix on this designation requires confirmation against the current INA catalog for exact performance classification; treat as a production variant marker until verified with the documentation package.

Application Suitability

What Polyamide Cage Failure Looks Like on a 40mm Needle Roller

A cage material mismatch on the INA NKI40/30-TV-XL needle roller bearing can turn a routine replacement into a seized shaft within days.

I once watched a mining conveyor in Chile run perfectly for a week after the maintenance crew substituted a stamped steel cage equivalent for a polyamide-caged needle roller. The vibration environment exceeded what thin steel cages tolerate at moderate speeds, and the cage shattered during a shift change. The shaft scored, the housing deformed, and what should have been a twenty-minute swap turned into a multi-day teardown. That failure had nothing to do with the base designation — bore, OD, and width all matched. It was purely a cage material decision made without checking the suffix. [NEED_CITE: rolling bearing failure mode classification per ISO 15243]

Matching the Cage to the Speed Envelope

The polyamide cage on the INA NKI40/30-TV-XL needle roller bearing keeps rotating mass low, which matters when this 40x55x30mm unit runs at the higher end of its speed range in electric motor or gearbox applications. Lighter cage weight means less centrifugal force on the needle rollers, reducing skidding risk during rapid acceleration. When we cross-reference this bearing for a client replacing an OEM component, we confirm the cage suffix alongside bore and OD — because a steel-caged lookalike will survive the load but may not survive the speed.

Radial Load, Compact Envelope, No Room for Error

Needle rollers in a 40mm bore, 55mm OD package carry heavy radial loads in a cross-section that leaves minimal room for tolerance stack-up. The single-row configuration concentrates load capacity into a narrow axial footprint, which is exactly why equipment designers choose this format for gearboxes and transmission layshafts. The operating temperature envelope for polyamide cages typically caps well below what brass or steel cages tolerate, so if the application involves sustained heat from adjacent components — like a hydraulic pump housing — the thermal limit of the TV cage must be checked against actual operating conditions. Lubrication intervals on open-type bearings depend entirely on the equipment builder's external seal and re-greasing schedule, since there is no integrated seal retaining grease at the bearing faces. [NEED_CITE: polyamide cage temperature limits in needle roller applications]

Why the Inner Ring Changes Everything

The NKI designation means this bearing ships with a dedicated inner ring, which matters when the shaft itself cannot be hardened and ground to serve as a raceway. The inner ring provides the correct surface finish and hardness for the needle rollers to track against, preventing premature shaft wear. If a maintenance team substitutes an NK variant — same rollers and cage, but designed to run directly on a hardened shaft — they may find the bore fits but the raceway surface degrades within weeks. We flag this distinction during every cross-reference check so that buyers sourcing replacements by OEM equipment number end up with the correct inner-ring configuration.

The Cost of Skipping Suffix Verification

An incorrect clearance class or cage substitution does not announce itself at installation. The bearing fits, the shaft turns, the machine runs — until thermal expansion closes the internal clearance under operating temperature, or the cage fatigues under a vibration profile it was never rated for. ISO 281 life calculations assume correct internal geometry and lubrication; a mismatched suffix voids that calculation silently. The result is unplanned downtime that shows up as a production loss rather than a bearing line item on the failure report. [NEED_CITE: bearing life calculation dependency on internal clearance per ISO 281]

Why Procurement Engineers Keep Coming Back

Our sourcing model for INA needle rollers is built around authorized distributor channels, not grey-market aggregators. Each INA NKI40/30-TV-XL needle roller bearing order ships with traceability documentation linking the batch back through the supply chain. We run cross-reference comparisons that align cage material, clearance, and precision — not just the base number — so substitutions are technically sound. For importers dealing with customs, we provide country-of-origin documentation and HS code support. When a buyer needs to verify authenticity, we walk them through the QR verification pathway using INA's official app, rather than asking them to trust a sticker on a box.

Documentation & Authenticity

• Supplier Certificate of Conformity tied to the specific batch number of your INA NKI40/30-TV-XL shipment
• Country-of-origin documentation confirming German manufacture for customs clearance and import compliance
• QR code verification pathway through INA's official application for on-site authenticity confirmation at receiving
• Dimensional inspection data available to confirm bore, OD, and width tolerances against ISO 492 before installation
• Material and batch traceability records linking each bearing back through authorized distributor channels

Storage, Handling & Mounting

• Keep the NKI40/30-TV-XL in its original sealed packaging until the moment of installation; polyamide cages absorb moisture over time, and early unsealing in humid storerooms can compromise dimensional stability
• Store below 30°C and away from direct UV exposure to protect the polyamide cage material from long-term degradation before the bearing reaches the shaft
• Handle with clean, lint-free gloves — the open-type design means any contaminant introduced during handling goes directly onto the needle roller contact surfaces with no seal to block it
• Use induction heating on the inner ring for interference fits rather than pressing through the cage and roller assembly, which can crack the polyamide cage fingers on this TV-suffix unit
• Establish an external lubrication schedule appropriate to the application since the open design relies entirely on the equipment builder's sealing and re-greasing infrastructure

Request a Quotation or Technical Review

Share your operating parameters — radial load, speed, ambient temperature, and lubrication method — so we can confirm this designation matches your application or recommend a better-suited variant. If you are replacing an existing bearing by OEM equipment number, send us the nameplate details and we will cross-reference the exact suffix configuration required. Ask for the full documentation package including origin papers and batch traceability before confirming your order.

Frequently Asked Questions

Q: How can I verify the authenticity of an INA NKI40/30-TV-XL needle roller bearing after delivery? A: Scan the QR code on the packaging using INA's official verification app, which checks the batch against the manufacturer's database. We also supply a Certificate of Conformity with batch traceability so you can reconcile the physical bearing against the shipping documentation.

Q: What does the TV suffix mean for cage material, and does it limit operating temperature? A: TV designates a polyamide cage, which is lighter than steel and reduces noise at moderate speeds. Polyamide cages have a lower continuous temperature limit than brass or machined steel cages, so confirm the operating temperature envelope for your specific application before specifying this variant.

Q: Can I substitute a generic NKI40/30 without suffixes for this bearing? A: The base designation NKI40/30 matches the bore, OD, and width, but omitting the TV suffix means the cage material may differ. A steel-caged equivalent will handle the same radial load but may behave differently at speed or under vibration. We match all suffixes during cross-reference to prevent field failures.

Q: Is the XL suffix a standard INA designation, and how does it affect specifications? A: The XL suffix appears on certain INA production batches and typically relates to manufacturing or packaging classification rather than a change in load capacity or dimensions. We recommend confirming its specific meaning against the documentation package accompanying your shipment.

Q: What lubrication approach is required for this open-type needle roller bearing? A: Since the NKI40/30-TV-XL has no integrated seals, lubrication depends on the equipment's external sealing and grease delivery system. Oil bath, circulating oil, or periodic re-greasing through housing ports are all viable; the choice depends on speed, temperature, and contamination exposure in your application.

[Confirm Availability and Request Documentation] Send your application parameters or OEM equipment number to our technical team for a cross-reference review and quotation with lead time on the INA NKI40/30-TV-XL needle roller bearing. Reach us through your existing account contact or initiate an inquiry through our sourcing channels.