1 Model Information & Technical Parameters

Model：NN 3006 KTN/VQ497

Dimensions

Bore d：30 mm

Outer diameter D：55 mm

Width B：19 mm

Bore type: 1:12 tapered bore

Code Explanation

NN: Double row cylindrical roller bearing, inner ring double ribs, outer ring ribless, separable inner and outer rings

3006: Size series 30, size code 06, nominal bore 30 mm

K: 1:12 tapered bore, preload adjustable by axial compression of inner ring

TN: Solid polyamide roller-guided cage, low friction and low temperature rise

VQ497: Custom stabilized heat treatment. Deep cryogenic stabilization reduces retained austenite, releases internal stress, restrains dimensional creep and improves long-term precision stability

Load Characteristics

Permitted load: Radial load only; axial load capacity is extremely low and cannot bear axial force independently

Structure: Separable design, inner ring double ribs, TN polyamide cage

Limiting speed: Polyamide cage provides superior high-speed performance versus brass cage; limiting speed depends on lubrication, oil-air lubrication achieves higher speed than grease lubrication

Pre-grease: No pre-filled lubricant, lubricant added during assembly

Logistics & Industry Codes

Net weight：0.18 kg

Indicative carbon footprint：0.26 kg CO₂e

eClass code：23-05-09-01

UNSPSC code：31171505

Suffix Explanation

NN: Double row cylindrical roller bearing without outer ribs. Inner and outer rings separable, rollers restrained by inner ring ribs.

K: 1:12 tapered bore, classic spindle construction. Axial lock nut expands inner ring radially to adjust preload during assembly.

TN: Polyamide (nylon) cage, lightweight with low friction and less heat generation. Continuous operating temperature recommended ≤120°C.

VQ497: Custom stabilization heat treatment. Compared with standard process, residual stress is significantly reduced, resisting dimensional variation induced by temperature cycles and long-term load, slowing precision degradation under continuous operation.

Important reminder: Ribless outer ring cannot support axial load alone. Spindle system must adopt matched precision angular contact ball bearings for axial force. Avoid continuous temperature above 120°C for polyamide cage; brass cage variant for high-temperature conditions. Preload must be precisely controlled for tapered bore; excessive preload causes overheating and premature fatigue. Hammer striking assembly prohibited; hydraulic nut pressing or thermal mounting recommended. Standard heat treatment alternative: NN3006 KTN. Precision grades /SP or /UP can be added upon request. Straight bore variant: NN3006 TN/VQ497.

2 Structure & Operating Characteristics

NN 3006 KTN/VQ497 double row cylindrical roller bearing adopts twin parallel roller rows delivering excellent radial rigidity. The 1:12 tapered bore enables flexible preload adjustment during assembly. TN polyamide cage minimizes friction and temperature rise under high speed. The core advantage is VQ497 stabilized heat treatment, greatly improving dimensional stability during long continuous operation, reducing creep deformation and retaining rotational precision over time. Separable inner and outer rings simplify spindle disassembly and maintenance.

Selection reference:

NN3006 KTN/VQ497 (taper bore polyamide cage + VQ497 stabilized heat treatment, precision spindles for long continuous production)

NN3006 KTN (taper bore polyamide cage standard heat treatment, conventional intermittent processing machines)

NN3006 TN/VQ497 (straight bore polyamide cage VQ497 heat treatment, preset-preload spindle modules)

NN3006 K/VQ497 (taper bore brass cage VQ497, continuous high-temperature service)

7006 angular contact ball bearings: Paired to carry spindle axial loads.

3 Core Performance Advantages

1. Double-row roller layout offers large radial load capacity and high radial rigidity to reduce spindle radial deflection.

2. 1:12 tapered bore allows accurate preload tuning during assembly to adapt to varied cutting loads and speed ranges.

3. TN polyamide cage features low friction, less heat generation and outstanding high-speed performance.

4. VQ497 dedicated stabilized heat treatment delivers low internal stress and anti-creep property, slowing precision loss during prolonged operation.

5. Separable inner and outer rings simplify disassembly, maintenance and bearing replacement of spindle units.

4 Typical Application Fields

4.1 High-speed precision machine tool spindles for continuous mass production

Vertical machining center spindles for mass production, CNC lathe spindles on automated lines, cylindrical & internal grinder spindles

4.2 High-precision rotary mechanisms requiring sustained precision around the clock

Automatic gear grinding equipment, precision CNC rotary tables for continuous duty, long-running precision dividing heads

4.3 Medium-high speed rotary machinery with high radial rigidity, requiring on-site preload adjustment and priority on long-term precision stability

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

Bearing assembly shall be performed in clean dust-free environment. All mating components must be thoroughly cleaned to remove chips and contaminants. Apply uniform axial preload on tapered bore inner ring via hydraulic nut; hitting bearing face is forbidden. Preload magnitude must be accurately controlled to avoid overheating caused by excessive preload. Conduct no-load temperature run-in after assembly. Geometric tolerances of shaft journal and housing bore must satisfy precision spindle bearing requirements. Observe temperature limit of polyamide cage and avoid prolonged over-temperature operation.

5.2 Selection Guidance

Long uninterrupted production, demand for precision durability, adjustable preload and temperature control → NN3006 KTN/VQ497

Intermittent machining, no long continuous operation, cost control → NN3006 KTN

Sustained high operating temperature, higher cage heat resistance required → NN3006 K/VQ497

No on-site preload adjustment needed, spacer preset preload structure → NN3006 TN/VQ497

Significant axial load exists: Combine this bearing with matched 7006 series precision angular contact ball bearings.

5.3 Lubrication Maintenance Instruction

No lubricant pre-filled at factory. High-speed bearing grease for medium-low speed; oil-air lubrication preferred for high-speed spindles. Long-term oil bath lubrication is not recommended. Target steady-state temperature rise ≤25K; avoid continuous temperature over 120°C for polyamide cage. Inspect preload and lubrication supply if temperature rises abnormally and continuously.

5.4 Environmental Application Notes

No built-in seals. Spindle assembly must install oil seals or labyrinth seals to prevent ingress of coolant and dust. Long-term axial load and shock loads are prohibited; impact indentations on rollers and raceways permanently damage rotational precision. Avoid wide repeated temperature fluctuations. Although VQ497 improves stability, extreme thermal cycling still accelerates performance degradation.

6 Fault Identification

Common failure modes: Abnormal temperature rise during operation, progressive growth of spindle radial runout, periodic abnormal noise, impact indentations on raceways, roller fatigue spalling, slow precision drift after long running. Halt equipment immediately once precision declines obviously or continuous abnormal noise occurs. Bearings with damaged raceways or rollers cannot be repaired and require complete replacement.