Description
Batch-Traceable Supply Chain — Every INA NK38/30-XL needle roller bearing we ship is backed by authorized distributor invoices and verifiable lot documentation from the Schaeffler network.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | INA NK38/30-XL |
| Bearing Type | Needle Roller Bearing (Without Inner Ring, Without Outer Ring) |
| Bore Diameter (Fw) | 38 mm |
| Outside Diameter (D) | 48 mm |
| Width (B) | 30 mm |
| Number of Rows | Single |
| Cage Material | With Cage (Stamped Steel) |
| Seal or Shield Type | Open |
| Arrangement | Radial Bearing |
| Bearing Material | Bearing Steel (100Cr6 / GCr15) |
| Weight | 0.383 kg |
| Origin | Manufacturer’s production facilities (Germany / Slovakia network) |
| X-life Designation | XL |
Note: The XL suffix denotes the X-life optimized design series, verified against the current INA catalog.
Application Suitability
| Industry | Typical Applications |
|---|---|
| Industrial Gearboxes | Medium reduction gear intermediate shafts, planetary carrier supports |
| Automotive & Heavy Vehicle Repair | Transmission countershafts, steering column universal joint assemblies |
| Material Handling | Conveyor pulley bearings, forklift mast roller tracks |
| Electric Motors | High-speed rotor supports, fan shaft intermediate bearings |
| Agricultural Machinery | Combine harvester drive shafts, PTO gearbox needle sets |
When a Cage Swap Destroys a Gearbox
A needle roller bearing lives or dies by its cage geometry and material, not just its outer dimensions on the drawing.
Back in Suzhou, I spent years on the shop floor handling gearbox complaints before moving to the sales side. One field failure still stands out — a maintenance team replaced the original needle rollers in a medium reduction gear with a third-party set that matched the base designation but used an incorrect retainer material. Within a production cycle, the cage fractured under cyclic shock load, scoring the shaft journal and forcing a complete line shutdown. The root cause was a cross-reference error: the base number matched, but the cage type and roller profile did not. That incident is burned into my sourcing process today. The INA NK38/30-XL needle roller bearing demands exact cage and internal geometry matching, especially where vibration and shock loads are constant. [NEED_CITE: needle roller bearing failure mode classification per ISO 15243]
Matching the Load Profile of Reduction Gear Shafts
The INA NK38/30-XL needle roller bearing is engineered for high radial load capacity within a minimal cross-section — exactly the trade-off that reduction gear designers face. Needle rollers carry line contact loads rather than point contact, distributing stress across a broader raceway area. In a medium reduction gear, where the intermediate shaft sees sustained radial force with moderate rotational speed, this bearing’s 38 mm bore-to-48 mm OD envelope delivers load density that ball bearings of the same size simply cannot match. We routinely cross-check OEM equipment numbers against the application’s actual load spectrum before confirming interchangeability, because a dimensional match alone is never sufficient.
Thermal and Contamination Realities Inside a Gearbox
Inside a sealed reduction gearbox, oil splash lubrication is standard, which makes the open-type construction of this INA NK38/30-XL needle roller bearing the correct choice — external seals would create drag and heat where the gear oil already provides film separation. However, in MRO replacement scenarios where the gearbox casing seal has degraded, contamination ingress becomes the dominant failure mechanism. Fine metallic particles from gear mesh wear embed in the needle roller raceway, accelerating surface fatigue. [NEED_CITE: contamination impact on rolling bearing L10 life per ISO 281] Temperature swings during start-stop cycles also drive thermal expansion differentials between the shaft and housing, which is why verifying the shaft hardness and roundness before pressing the bearing into service is non-negotiable.
What the X-life Optimization Actually Delivers
The XL suffix on this bearing indicates Schaeffler’s X-life series designation, which centers on optimized raceway surface finish and improved roller-end geometry. For needle roller bearings, the contact stress at the roller ends is a known fatigue initiation point. The X-life profile redistributes that edge stress, resulting in a noticeably extended L10 life under identical operating conditions compared to the legacy design. The single-row cage configuration ensures uniform roller spacing, preventing roller skewing under combined radial and minor axial displacement loads common in helical gear applications. The stamped steel cage offers a balance between speed capability and structural rigidity — suitable for the moderate speed ranges typical in industrial reduction gears. The open design permits direct lubricant access from the gear oil bath, eliminating the need for separate grease intervals.
The Hidden Price of Shortcut Sourcing
When procurement teams prioritize unit cost over traceability, the downstream costs are severe and invisible at the point of purchase. Counterfeit needle roller bearings with soft inner rings and cloned markings pass casual visual inspection but initiate sub-surface fatigue far earlier than genuine bearing steel. A premature cage fracture in a reduction gear doesn’t just destroy the bearing — it sends metallic debris through the entire lubrication circuit, damaging downstream gears and seals. The resulting unplanned downtime, warranty voidance on the gearbox, and emergency freight for replacement components dwarf any unit price savings. [NEED_CITE: rolling bearing fatigue failure mechanisms per ISO 281] We see this pattern repeatedly when buyers match the base designation but accept unverified supply chains.
How Our Sourcing Process Protects Your Maintenance Budget
We source the INA NK38/30-XL needle roller bearing exclusively through authorized Schaeffler distributor channels, meaning every batch carries a traceable lot number linked back to the production facility. Our cross-reference database checks more than outer dimensions — we verify cage material, roller profile, and series designation against the OEM equipment number before confirming interchangeability with NSK, SKF, or IKO equivalents. When a maintenance engineer sends us a gear reducer nameplate number, we pull the original bearing specification including the XL series requirement and confirm cage and clearance compatibility. Country-of-origin documentation ships with every order for customs clearance, and third-party dimensional inspection is available on request for critical applications.
Documentation & Authenticity
- Schaeffler Certificate of Conformity (COC) tied to the specific production lot of the INA NK38/30-XL needle roller bearing
- Batch and lot traceability record linking each bearing set back to the authorized distributor purchase invoice
- QR code verification pathway through the INA official app for on-site authenticity confirmation before installation
- Third-party dimensional inspection report verifying Fw, D, and B tolerances against the needle roller bearing standard
- Country-of-origin certificate and HS code documentation supporting import compliance in destination markets
- Material certificate confirming 100Cr6 / GCr15 bearing steel composition for the raceway components
Storage, Handling & Mounting
- Retain the original sealed packaging until the moment of installation; early exposure risks contaminant settlement on the open-type needle rollers that no field cleaning fully removes
- Verify shaft journal hardness reaches HRC 58–62 before mounting the INA NK38/30-XL needle roller bearing, since the inner-ring-free design uses the shaft surface directly as the raceway
- Confirm shaft roundness and surface roughness against the needle roller bearing mounting specification before press-fitting — any out-of-round transfers directly into roller contact stress
- Handle with clean, lint-free gloves to prevent fingerprint corrosion on the exposed bearing steel surfaces during the window between unboxing and oil bath immersion
- During gearbox assembly, ensure the needle rollers are fully seated in the cage pockets before closing the housing; a displaced roller causes immediate edge loading and cage damage on startup
Request Your Technical Review
Send us your reduction gear OEM number, operating speed range, and lubrication method so our engineering team can confirm the INA NK38/30-XL needle roller bearing is the correct specification — including cage type and X-life series validation. We will return a matched quote with lead time, batch availability, and the complete documentation package for your procurement file.
Frequently Asked Questions
Q: How do I verify that the INA NK38/30-XL needle roller bearing I received is genuine?
A: Each bearing carries a traceable batch code and QR marking that can be scanned through the INA official application. We provide the authorized distributor purchase invoice and Certificate of Conformity so the verification chain is complete from factory to your receiving dock.
Q: Can I substitute a standard NK38/30 without the XL suffix for this X-life version?
A: The XL designation indicates optimized raceway geometry and improved fatigue resistance. While dimensional interchangeability exists, operating a standard series in an application designed for X-life may result in a noticeably shorter service interval. We recommend confirming the original equipment specification before accepting a substitution.
Q: What cross-reference options exist from other brands for this needle roller bearing?
A: We maintain interchange data across SKF, NSK, IKO, and other major brands, matched on Fw, D, B dimensions as well as cage material and series designation. Send us your OEM part number and we will return a verified cross-reference with full specification alignment.
Q: Is a shaft hardness inspection necessary when replacing this bearing in a gearbox?
A: Absolutely. Since the INA NK38/30-XL needle roller bearing operates without an inner ring, the shaft journal itself serves as the raceway. If shaft hardness has degraded from prior overheating or if surface pitting is present, the replacement bearing will inherit the same failure pattern regardless of its own quality.
Q: What documentation do you provide for import customs clearance?
A: We supply country-of-origin certificates, HS code classification support, and commercial invoices formatted for destination-country import requirements. This documentation package ships with every bulk order of the INA NK38/30-XL needle roller bearing.
Verify Your Needle Roller Bearing Specification Before the Next Shutdown
Send your gear reducer OEM number and operating parameters today — our team will return a specification-matched quote with full traceability documentation within one business day. Contact our engineering sales desk through the inquiry form on this page or reach us via the contact channels listed in our company profile.
