DKFL NA 6912 Needle Roller Bearing
The DKFL NA 6912 belongs to the class of machined needle roller bearings with integral retaining flanges and an independent, separable inner ring. Engineered for shafts with a 60 mm bore diameter, an outside diameter of 85 mm, and a wide 45 mm profile, this bearing provides high radial stiffness and load support. Compared with the narrower 49 series (which measures 25 mm wide in this size), the 69 series delivers significantly greater contact length along the needle rollers, making it well-suited for heavy-duty radial and oscillating loads.
10060101865
Request a quote
Product Detail
Needle Roller Bearing DKFL NA 6912 Machined Needle Roller Bearing with Inner Ring | 60 mm Shaft Diameter | Extra-Wide Industrial Design
Engineered for maximum radial load capacity within a compact cross-section, the DKFL NA 6912 features a hardened machined inner ring, precision needle rollers, and outer ring lubrication features for demanding industrial applications under DKFL quality assurance at Kamyar Gostar Iranian (KGICO).
Technical Overview of the DKFL NA 6912 Needle Roller Bearing
The DKFL NA 6912 belongs to the class of machined needle roller bearings with integral retaining flanges and an independent, separable inner ring. Engineered for shafts with a 60 mm bore diameter, an outside diameter of 85 mm, and a wide 45 mm profile, this bearing provides high radial stiffness and load support. Compared with the narrower 49 series (which measures 25 mm wide in this size), the 69 series delivers significantly greater contact length along the needle rollers, making it well-suited for heavy-duty radial and oscillating loads.
The inclusion of a precision-ground, case-hardened inner ring eliminates the requirement for direct shaft hardening and ground raceway preparation. Furthermore, an integrated circumferential lubrication groove and through-holes on the outer ring facilitate continuous lubricant delivery to the rolling elements, reducing friction and extending component service life under heavy industrial duty cycles.
Nomenclature and Designation Analysis (DKFL NA 6912)
Prefix "NA": Identifies a machined needle roller bearing with retaining flanges, supplied with an independent inner ring.
Dimension Series "69": Denotes the heavy-duty, extra-wide dimensional series designed to house long needle rollers or multiple roller rows for increased dynamic load ratings.
Bore Code "12": Multiplied by 5 (12 × 5 = 60 mm), designating a nominal inner diameter of 60 mm.
Lubrication Feature: Features a dedicated annular groove and radial oil holes located on the outer ring for smooth re-lubrication.
DKFL: High-precision industrial bearing brand known for strict metallurgical control, supplied and warranted by Kamyar Gostar Iranian (KGICO).
Engineering Specifications and Dimensions
| Bore (d) | Outer Diameter (D) | Total Width (B) | Roller & Cage Assembly | Inner Ring Status | Lubrication System | Approx. Weight | Material |
|---|---|---|---|---|---|---|---|
| 60 mm | 85 mm | 45 mm | Precision needle rollers with steel cage | Included (Hardened & Ground) | Annular groove & holes in outer ring | Approx. 0.92 kg | 100Cr6 High-Carbon Chrome Steel |
Technical Comparison: NA 6912 vs. Equivalent 60 mm Shaft Options
Comparative technical analysis of needle roller bearing configurations for 60 mm shaft systems:
| Bearing Designation | Dimensions (d × D × B) | Inner Ring | Radial Load Capacity | Primary Engineering Advantage |
|---|---|---|---|---|
| NA 6912 (DKFL) | 60 × 85 × 45 mm | Included (Ground) | Maximum (45 mm Wide) | Superior load distribution and moment rigidity without requiring hardened shafts |
| NA 4912 | 60 × 85 × 25 mm | Included | Standard / Moderate | Standard width suited for narrow housing geometries |
| RNA 6912 | 68 × 85 × 45 mm | None (Without Inner Ring) | Very High | Rollers run directly on a hardened and ground shaft to maximize radial compactness |
Key Features and Competitive Advantages of DKFL NA 6912
45 mm Extra-Wide Profile
An extended linear contact line disperses localized peak pressures over a broader surface area, effectively preventing premature brinelling.
Separate Precision Inner Ring
Enables immediate mounting onto conventional commercial shafting without the need for induction hardening or secondary surface grinding.
Integrated Relubrication Channels
Machined annular groove and cross-drilled lubrication ports allow fluid grease or oil delivery across the full active roller contact zone.
Robust Steel Retaining Cage
Accurately guides and spaces the needle rollers, suppressing roller skewing and friction during rapid acceleration and reversing duty cycles.
Premium 100Cr6 Chrome Steel
Precision heat treatment yields a core hardness of 58–62 HRC, providing high resistance to wear, micro-spalling, and contact fatigue.
Guaranteed DKFL Quality
100% inspected for dimensional accuracy and radial runout tolerances, backed by Kamyar Gostar Iranian technical support and verification.
Primary Industrial Applications for the NA 6912
- Industrial Gearboxes and Heavy Reducers: Shaft assemblies where severe radial gear mesh forces exist in tight housing geometries.
- Hydraulic Piston Pumps and Fluid Motors: Reliable 60 mm shaft seating against high-frequency hydraulic pressure pulses.
- Textile Machinery and Heavy Rotary Printing: Continuous high-speed roller support requiring minimal radial deflection.
- Packaging Lines and Material Handling Rolls: Conveyor drums and guide cylinders demanding high rigidity and vibration absorption.
- Mechanical Presses and Cutting Machinery: Shaft mountings subject to repeated shock loads and oscillatory movements.
Installation Guidelines and Engineering Instructions
When press-fitting the outer ring into the housing bore, ensure that the outer ring lubrication holes line up precisely with the housing grease fitting or oil duct to prevent blocking lubricant replenishment channels.
The NA 6912 needle roller bearing is strictly rated for pure radial loads. The machined integral flanges only guide the rollers and cannot accept axial thrust forces. Applications with axial thrust must incorporate dedicated thrust ball or roller bearings.
Independent Ring Assembly Practice
The separable inner ring should be mounted onto the 60 mm shaft first, preferably using an induction heater or mechanical fitting tool. The outer ring with the roller assembly is pressed square into the housing bore. When joining the shaft into the housing, apply a slow, rotating movement to ensure the rollers enter without scoring the precision inner raceway.
Frequently Asked Questions (FAQ)
1. What is the difference between NA 6912 and RNA 6912?
The NA 6912 includes an independent, ground inner ring suited for a standard 60 mm shaft. The RNA 6912 is supplied without an inner ring; its rollers run directly on an appropriately hardened (58–64 HRC) and precision-ground 68 mm shaft diameter, saving radial space.
2. Why choose the NA 6912 over the NA 4912?
The 69 series provides a 45 mm width versus 25 mm for the 49 series. This wider configuration roughly doubles roller contact length, significantly increasing dynamic and static radial load capacity for heavy-duty drive systems.
3. What lubrication type is suitable for the DKFL NA 6912?
For standard industrial speeds and heavy loads, a lithium-complex grease with extreme pressure additives (EP2) is recommended. In continuous high-speed or elevated temperature applications, an oil bath or circulating oil system should be utilized.
Inquire and Purchase DKFL NA 6912 Needle Roller Bearings
Contact the engineering and sales specialists at Kamyar Gostar Iranian (KGICO) for stock availability, volume quotations, CAD drawings, and technical consultations.
Check Stock & Place Order at kgico.co