1 Model Information & Technical Parameters

Model：NN 3013 KTN/SP

Dimensions

Bore d：65 mm

Outer diameter D：100 mm

Width B：26 mm

Bore type: 1:12 tapered bore

Radial clearance: C1 minimal internal clearance

Accuracy class: SP precision grade

Structure: NN double row design, inner ring with three ribs, ribless outer ring, double sets of rollers

Outer ring flange: None

Seal: Open design, no seals

Surface coating: Uncoated

Pre-lubrication: No lubricant supplied from factory

Re-lubrication feature: No circumferential lubrication groove & oil holes on outer ring, continuous on-line re-lubrication not available

Code Explanation

NN: Double row cylindrical roller bearing, three ribs on inner ring, ribless outer ring. Two rows of rollers share radial loads simultaneously.

3013: Size series 30 medium cross-section spindle bearing with outstanding load capacity.

K: 1:12 taper on inner bore

TN: Solid polyamide non-metallic roller-guided cage, low friction and controllable temperature rise under continuous high-speed operation.

SP: Precision accuracy grade with strictly controlled rotational runout for precision machine tool spindle applications.

Load & Speed Data

Basic dynamic load rating Cr：76.5 kN

Basic static load rating C0r：116 kN

Permissible speed, grease lubrication：9 000 r/min

Permissible speed, oil-air lubrication：10 000 r/min

Material & Additional Properties

Material: Bearing steel

Indicative carbon footprint：2.5 kg CO₂e

Net weight：0.663 kg

eClass code：23-05-09-01

UNSPSC code：31171505

Suffix Explanation

NN: Double row cylindrical roller bearing. Three ribs on inner ring constrain two roller rows; ribless outer ring. Radial rigidity and load capacity are much higher than single row bearings. Limited bidirectional axial locating capacity allows moderate axial loads.

3013: Series 30 spindle-dedicated double row bearing. Balanced cross-section optimizes both load capacity and speed performance, widely used for CNC spindle support.

K: 1:12 tapered inner bore. Axial displacement of inner ring via lock nut enables adjustable preload during assembly.

TN: Polyamide cage, lightweight non-metallic structure with low friction coefficient, ensuring stable temperature and low noise during long continuous operation.

SP: Precision accuracy grade. Dimensional tolerance, radial and axial runout are tighter than standard bearings to maintain stable machining precision under high speed and heavy loads.

C1 clearance: Minimal radial internal clearance, matched for lightly preloaded spindle systems to suppress vibration and improve workpiece surface finish.

Important reminder: This 1:12 tapered-bore NN-type double row cylindrical roller bearing supports on-site preload adjustment during assembly. No W33 circumferential lubrication groove on outer ring, cannot connect to continuous automatic lubrication circuits, only suitable for intermittent production with one-time grease filling during mounting. Double-row design provides high rigidity and load capacity, yet limiting speed is lower than single row cylindrical roller bearings of equal dimensions. Moderate bidirectional axial loads can be sustained; matched angular contact ball bearings are recommended for heavy axial forces. Open bearing without built-in seals; labyrinth seals or oil seals must be installed on housings to block coolant and dust ingress. No pre-filled grease upon delivery; lubricant should be filled during assembly. Never strike inner or outer ring directly during assembly to prevent indentations on raceways and rollers.

Alternative variants:

NN3013 KTN/SPW33 (1:12 tapered bore, with W33 lubrication groove, supporting continuous on-line re-lubrication)

NN3013 TN/SP (straight cylindrical bore, preload non-adjustable, no lubrication groove)

NN3013 TN/SPW33 (straight bore with W33 groove, fixed preload for continuous lubrication production line)

NN3013 KTNHA/SP (high-temperature polyamide cage for intermittent spindles under elevated temperature)

NN3013 KTN/UP (UP ultra-precision grade for ultra-high precision mirror machining spindles)

2 Structure & Operating Characteristics

NN 3013 KTN/SP is an SP-grade precision double row cylindrical roller bearing with C1 minimal radial clearance, TN polyamide cage, 1:12 tapered bore and outer ring without lubrication groove. Symmetric double-row roller layout delivers significantly improved radial load capacity and rigidity compared with equivalent single row bearings, together with limited axial locating ability, making it an adjustable-preload mainstream radial support for precision machine tool spindles. The NN design with three inner ring ribs restricts roller axial movement; thermal elongation compensation is inferior to floating N-type single row bearings.

The core advantage is the 1:12 tapered bore. Axial movement of inner ring driven by lock nut changes effective internal clearance, allowing flexible preload setting during assembly to satisfy different machining requirements. Without outer ring W33 channel, uninterrupted re-lubrication during running is impossible, only applicable to intermittent processing equipment with scheduled downtime for grease replenishment. Combined C1 minimal clearance and precision manufacturing tolerances reduce rotary vibration under high speed and heavy cuts, stabilizing dimensional accuracy in finishing operations.

Selection guide:

NN3013 KTN/SP (1:12 tapered bore without W33 groove, SP C1 clearance, on-site adjustable preload, intermittent processing with one-time greasing)

NN3013 KTN/SPW33 (1:12 tapered bore with lubrication groove, adjustable preload plus continuous on-line lubrication for mass production)

NN3013 TN/SP (straight bore without groove, fixed interference preload, non-adjustable)

NN3013 TN/SPW33 (straight bore with W33 groove, fixed preload for automatic continuous lubrication system)

NN3013 KTNHA/SP (heat-resistant cage for intermittent equipment under high ambient temperature)

NN3013 KTN/UP (ultra-precision grade for heavy-duty high-precision grinding spindles)

Recommended matching bearing: Paired 7013 SP angular contact ball bearings to carry primary axial loads.

3 Core Performance Advantages

1. NN double-row roller arrangement achieves high radial load capacity and extreme rigidity, suitable for heavy cutting and heavy-load finishing processes.

2. 1:12 tapered inner bore enables on-site preload adjustment via lock nut during assembly, flexibly adapting to roughing and finishing working conditions.

3. TN polyamide non-metallic cage guarantees stable rotation and low friction, offering excellent temperature control during long continuous operation.

4. SP precision standard combined with C1 minimal radial clearance delivers tight control over rotational runout, mitigates vibration under high speed and heavy loads and stabilizes machining accuracy.

5. Limited bidirectional axial locating capacity simplifies structural design of spindle support systems.

6. Bearing steel construction ensures stable contact performance of raceways and rollers with consistent performance during prolonged continuous operation.

4 Typical Application Fields

4.1 Vertical machining centers and small gantry machining center spindle units

Intermittent production, frequent process switching, spindle preload commissioning required, without 24-hour automatic continuous lubrication system

4.2 CNC cylindrical grinders, jig grinders precision spindles

Small & medium batch precision grinding, periodic shutdown maintenance for grease filling, adjustable preload demanded

4.3 Precision CNC lathes and turn-mill composite spindles

Multi-variety small-batch finishing, frequent process changeover requiring flexible spindle rigidity tuning

4.4 Test equipment, special precision high-speed rotary components

Repeated preload calibration, high-precision rotating machinery without uninterrupted automatic oil supply circuit

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

SP precision bearings should be assembled in constant-temperature dust-free clean workshops. Thoroughly remove contaminants on shaft journals, housing bores and spacer contact surfaces. For 1:12 tapered bore bearings, preload is adjusted by axially advancing inner ring through lock nut. Tighten nut slowly and evenly during assembly, inspect spindle rotary accuracy and temperature rise in real time to avoid over-preloading and overheating. No lubrication groove on outer ring; grease can only be filled during assembly, formulate regular shutdown maintenance plan for supplementary greasing. Reliable sealing must be installed on machine housings to prevent coolant and dust from reaching rolling surfaces. Paired angular contact bearings are recommended to share axial loads under heavy axial working conditions.

5.2 Selection Guidance

Intermittent production, no continuous on-line oil supply, preload adjustment required on site → NN3013 KTN/SP

Continuous mass production, automatic lubrication system, adjustable preload required → NN3013 KTN/SPW33

No on-site preload adjustment needed, intermittent processing with one-time greasing → NN3013 TN/SP

No on-site preload adjustment needed, equipped with automatic continuous lubrication system → NN3013 TN/SPW33

Elevated ambient temperature, intermittent continuous operation → KTNHA high-temperature cage version

Ultimate rotational accuracy, heavy-duty high-precision grinding → NN3013 KTN/UP

Important notice: No outer ring lubrication groove for this model, lubricant cannot be replenished while equipment is running, periodic maintenance schedule is mandatory. Although limited axial loads can be accommodated, sustained heavy axial force easily causes edge stress concentration and roller end scuffing.

5.3 Lubrication Maintenance Instruction

No lubricant pre-filled at factory. Oil-air lubrication is recommended to achieve maximum permissible rotational speed; grease one-time filling is widely adopted for intermittent working conditions. Lacking outer ring oil groove, grease cannot be supplemented into bearing without machine shutdown. Set maintenance cycle according to operating conditions, shut down periodically to disassemble end caps for re-greasing; prevent premature wear caused by long-term insufficient lubrication. Continuously monitor bearing temperature; stop operation immediately once abnormal temperature rise occurs to inspect preload and lubrication status.

5.4 Environmental Application Notes

Open structure without built-in seals; labyrinth seals or oil seals on housings are compulsory. Raceways and rollers are extremely sensitive to tiny hard particles. Contamination amplifies vibration and rapidly deteriorates machining accuracy. Severe shock loads should be avoided to prevent permanent indentations on rolling contact surfaces.

6 Fault Identification

Common failure modes: steadily rising vibration during heavy cutting, regular texture patterns on machined workpieces, abnormal continuous spindle temperature increase, periodic rotational noise, cage abrasion, roller end scuffing and raceway fatigue spalling. Typical failures for tapered bore bearings: persistent overheating caused by excessive preload adjustment; degraded rotary accuracy from insufficient preload; premature wear due to aged and exhausted grease without online replenishment; uneven load distribution between two roller rows and premature fatigue of single-side raceway under overloaded axial force. Shut down equipment immediately upon persistent abnormal noise or irreversible accuracy degradation. Bearings with permanent damage to raceways, rollers or cage cannot be repaired and need complete replacement.