1 Model Information & Technical Parameters

Model：NN 3010 KTN/UP

Dimensions

Bore d：50 mm

Outer diameter D：80 mm

Width B：30 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

3010: Size series 30, size code 10, nominal bore 50 mm, medium cross-section balancing radial rigidity and limiting speed

K: 1:12 tapered bore. Inner ring expands radially under axial tension from lock nut for adjustable preload during assembly

TN: Solid polyamide roller-guided cage; continuous operating temperature ≤120°C

UP: UP ultra-precision accuracy grade. Strict tolerances for raceway and rollers to achieve extremely low radial runout for high-precision finishing spindles

Load Characteristics

Mainly withstand bidirectional radial loads. Axial load capacity is very limited. Must be combined with angular contact ball bearings to bear axial cutting forces. Separable construction with double-row steel rollers and TN polyamide cage. UP grade delivers superior dimensional consistency and rotational accuracy.

Limiting speed: Stable performance under medium and high speed; oil-air lubrication recommended to fully utilize precision advantages.

Pre-grease: No pre-filled lubricant, add lubricant during assembly.

Logistics & Industry Codes

Net weight：0.21 kg

Indicative carbon footprint：0.23 kg CO₂e

eClass code：23-05-09-01

UNSPSC code：31171505

Suffix Explanation

NN: Double row cylindrical roller bearing, ribless outer ring, separable rings. Higher radial rigidity and load rating than single-row cylindrical roller bearings of equivalent size, widely used for spindle radial support.

3010: Medium cross-section Series 30 with balanced rigidity, general specification for various precision machine tool spindle units.

K: 1:12 tapered bore. Preload can be flexibly set via hydraulic or lock nut expansion, suitable for finishing and light-to-medium cutting.

TN: Polyamide roller-guided cage with low friction and low operating temperature. TNHA reinforced cage available for sustained high-temperature conditions.

UP: Ultra-precision grade. Strict control over roller grouping and raceway geometry to minimize spindle rotation error, suppress chatter and improve workpiece surface finish.

Important reminder: Cannot bear axial load independently. Match with precision angular contact ball bearings. Continuous temperature above 120°C is forbidden for TN cage. UP bearings require ultra-clean assembly environment; contaminants easily damage precision raceway surfaces. Preload must be precisely controlled; excessive preload leads to temperature surge and loss of precision stability. Hammer assembly prohibited; use hydraulic nut for uniform pressing.

Alternative variants:

NN3010 TN/UP (straight bore UP precision for modular fixed-preload motor spindles)

NN3010 KTNHA/UP (taper bore with high-temperature resistant TNHA cage)

NN3010 KTN (standard precision for general cutting applications)

2 Structure & Operating Characteristics

NN 3010 KTN/UP is an UP ultra-precision double row cylindrical roller bearing. Double-row roller arrangement provides high radial rigidity, and strict UP manufacturing tolerances reduce rotational runout significantly. The 1:12 tapered bore enables flexible preload adjustment during commissioning to balance low heat generation at high-speed finishing and rigidity for light cutting. Separable rings simplify spindle maintenance and disassembly.

Selection guide:

NN3010 KTN/UP (taper bore TN cage, UP grade for high-precision finishing spindles)

NN3010 TN/UP (straight bore UP precision for standardized modular motor spindles)

NN3010 KTNHA/UP (24-hour continuous finishing, elevated ambient temperature)

NN3010 KTN (standard precision for general-purpose spindles)

Recommended matching bearings: UP grade 7010 / 7210 series angular contact ball bearings to guarantee full spindle accuracy matching.

3 Core Performance Advantages

1. UP ultra-precision grade with tightly controlled raceway and roller geometry, low radial runout, greatly improving machining accuracy and surface quality.

2. NN double-row roller layout delivers higher radial rigidity and load capacity than single-row cylindrical roller bearings with identical bore size, balancing rigidity and rotational precision.

3. 1:12 tapered bore allows flexible on-site preload adjustment to adapt to multiple finishing processes, offering better adjustability than fixed-preload straight bore solutions.

4. Lightweight TN polyamide roller-guided cage features low friction loss and effectively controls temperature rise during medium-high speed finishing.

5. Separable inner and outer rings simplify maintenance and component replacement; Series 30 is a mature universal dimension for standardized spindle spare parts.

4 Typical Application Fields

4.1 High-precision finishing machine tool spindles

Precision CNC lathe spindles, high-accuracy internal & cylindrical grinder spindles, high-speed small-medium machining center spindles, turn-mill composite finishing spindles

4.2 Motor spindle units requiring strict rotational accuracy and surface finish

Precision grinding power heads on automated production lines, high-precision rotary fixtures, spindles for optical component processing equipment

4.3 High-end precision rotary mechanisms with heavy radial loads, adjustable assembly preload, low required runout, combined with precision angular contact ball bearings

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

UP ultra-precision bearings shall be assembled in constant-temperature, dust-free clean workshops. All shafts, housings and spacers must be thoroughly cleaned of chips, dust and oil. Apply preload evenly to tapered bore inner ring via hydraulic nut; hammering bearing faces is prohibited. Preload travel must be strictly monitored; excessive preload causes temperature rise and impairs long-term precision stability. After assembly, conduct long-duration no-load temperature run-in by gradually increasing speed from low rotation. Shaft journal and housing bore tolerances must comply with UP precision bearing standards; observe the 120°C temperature limit for TN cages.

5.2 Selection Guidance

High-precision finishing, adjustable on-site preload, low rotational runout required → NN3010 KTN/UP

Modular mass assembly, fixed spacer preload without on-site adjustment → NN3010 TN/UP

Non-stop long-hour finishing, elevated equipment operating temperature → NN3010 KTNHA/UP

General cutting, medium accuracy requirement, limited budget → NN3010 KTN

For significant axial loads: Combine this bearing with UP grade 7010 / 7210 precision angular contact ball bearings.

5.3 Lubrication Maintenance Instruction

No lubricant pre-filled at factory. High-speed precision spindle grease recommended for medium-low speed finishing; oil-air lubrication preferred for medium-high speed operation. Long-term oil bath lubrication is not recommended. Maintain steady-state temperature rise below 25K. Avoid continuous temperature exceeding 120°C for TN polyamide cages. Regularly monitor operating temperature and workpiece accuracy. Investigate lubricant contamination or preload decay if precision gradually deteriorates.

5.4 Environmental Application Notes

No integrated seals. Equip spindle assembly with oil seals or labyrinth seals to block coolant and abrasive dust. Precision UP raceways are sensitive to particle contamination; tiny hard particles create permanent indentations and destroy accuracy. Long-term axial load and shock loads are forbidden. Minimize frequent sharp thermal cycling to maintain bearing dimensional stability.

6 Fault Identification

Common failure modes: Deteriorated spindle rotational accuracy, periodic consistent chatter marks on workpieces, sustained temperature rise, periodic abnormal noise, indentations or fatigue spalling on raceways, roller end face wear. Stop operation immediately once machining accuracy cannot be recovered or persistent abnormal noise appears. Bearings with damaged raceways or rollers cannot be repaired and must be fully replaced.