1 Model Information & Technical Parameters

Model：NN 3016 KTN3/SPW33

Dimensions

Bore d：80 mm

Outer diameter D：125 mm

Width B：34 mm

Bore type: 1:12 tapered bore

Radial clearance: C1 minimal internal clearance

Accuracy class: SP precision grade

Structure: NN double row cylindrical roller bearing, three ribs construction; outer ring fitted with W33 annular lubrication groove and oil holes

Outer ring flange: None

Lubrication feature: W33 annular groove plus oil holes, support on-line re-lubrication during operation

Seal: Open design, no seals

Surface coating: Uncoated

Pre-lubrication: No lubricant supplied from factory

Number of rows: 2 rows of rollers

Code Explanation

NN: Double row cylindrical roller bearing with three ribs, bidirectional axial constraint for rollers, mainly designed for radial loads.

3016: Size series 30 spindle dedicated double row roller bearing featuring high rigidity.

K: 1:12 tapered inner bore, preload adjustable via axial pushing.

TN3: Improved non-metallic cage optimized for higher rotational speed.

SP: Precision accuracy grade meeting requirements of high-precision machine tool spindles.

W33: Outer ring equipped with annular lubrication groove and evenly distributed oil holes.

Load & Speed Data

Basic dynamic load rating Cr：119 kN

Basic static load rating C0r：186 kN

Permissible speed, grease lubrication：9 000 r/min

Permissible speed, oil-air lubrication：10 300 r/min

Material & Additional Properties

Rolling element material: Bearing steel

Indicative carbon footprint：5.3 kg CO₂e

Net weight：1.42 kg

eClass code：23-05-09-01

UNSPSC code：31171505

Suffix Explanation

NN: Double row cylindrical roller bearing with three ribs. Axial position of two roller rows is restricted; no relative axial floating between inner and outer ring, delivering high rigidity under radial loads only.

3016: Series 30 double row spindle bearing with sufficient cross-section width, radial stiffness far superior to single row bearings of identical dimension.

K: 1:12 tapered bore. Axial advance by lock nut expands bearing inner diameter to adjust preload on site.

TN3: Optimized non-metallic cage with better dynamic balance and lower churning heat at high speed.

SP: Precision dimensional and rotational accuracy for precision cutting and grinding spindles.

W33: Annular groove on outer ring periphery with oil holes to supply lubricant continuously while spindle operates.

C1 clearance: Minimal radial internal clearance, cooperated with tapered bore preload adjustment to suppress vibration and improve machined surface quality.

Important reminder: NN double row roller bearing prevents relative axial movement between rings and provides outstanding radial rigidity. The 1:12 tapered bore is the key feature for adjustable spindle preload. W33 lubrication groove enables non-stop on-line grease/oil replenishment, ideal for 24-hour continuous mass production. This bearing primarily carries radial loads; paired angular contact ball bearings are required to sustain axial force. Open bearing without built-in seals; oil seals or labyrinth seals must be installed on housings to isolate coolant and dust. No pre-filled grease upon delivery.

Alternative variants:

NN3016 TN/SP (straight cylindrical bore, SP precision, W33 groove, fixed preload without on-site adjustment)

NN3016 KTN3/UPW33 (1:12 tapered bore, UP ultra-precision grade, W33 groove, ultra-precision mirror finishing spindles)

N1016 TN/SP (single row straight bore, no lubrication groove, axially floating outer ring, intermittent machining without continuous oil supply)

2 Structure & Operating Characteristics

NN 3016 KTN3/SPW33 is an SP precision grade double row cylindrical roller bearing with C1 minimal radial clearance, TN3 improved non-metallic cage, 1:12 tapered bore, and outer ring integrated with W33 annular lubrication groove and oil holes. Double parallel roller layout greatly improves radial load capacity and rigidity compared with single row bearings of equal size. The three-rib NN structure limits axial sliding between inner and outer ring, minimizing spindle system deformation and enhancing anti-chatter performance during cutting.

Core features: High-rigidity double-row structure + adjustable preload via 1:12 tapered bore + continuous on-line lubrication with W33 groove. Combined with lock nut, the tapered bore allows flexible preload setting on site to adapt roughing and finishing processes. W33 groove evenly delivers lubricant into raceways, suitable for long-term non-stop mass production. Optimized TN3 cage further improves high-speed stability.

Selection guide:

NN3016 KTN3/SPW33 (tapered bore adjustable preload, W33 groove, high double-row rigidity, support continuous on-line lubrication, spindles for 24h mass production machining centers & grinders)

NN3016 TN/SP (straight bore fixed preload, W33 groove, continuously running spindles without frequent preload tuning)

N1016 TN/SP (single row straight bore, no lubrication groove, floating outer ring, intermittent production with scheduled shutdown maintenance)

NN3016 KTN3/UPW33 (tapered bore, UP ultra-precision grade, ultra-precision grinding and mirror processing equipment)

Recommended matching bearing: Paired 7016 SP angular contact ball bearings to bear all axial loads and realize bidirectional spindle axial positioning.

3 Core Performance Advantages

1. Double-row roller arrangement provides strong radial load capacity and high structural rigidity, outstanding anti-vibration performance under cutting conditions.

2. 1:12 tapered inner bore enables flexible on-site preload adjustment via axial pushing of lock nut, adaptable to various machining processes.

3. W33 outer ring annular lubrication groove and oil holes support continuous on-line lubricant replenishment during machine operation, meeting all-day mass production demands.

4. TN3 improved non-metallic cage features excellent dynamic balance at high speed, low churning loss and reliable temperature control.

5. SP precision standard together with C1 minimal radial clearance reduces rotational runout, effectively suppresses chatter marks and improves workpiece surface quality.

6. Three-rib NN structure eliminates axial floating and maintains stable spindle rigidity for consistent dimensional accuracy under heavy cutting.

4 Typical Application Fields

4.1 High-speed spindles of vertical / horizontal machining centers

24-hour continuous mass production, requiring continuous on-line lubrication and adjustable on-site preload

4.2 Internal & external cylindrical grinders, tool grinding spindles

High radial rigidity for long uninterrupted grinding cycles

4.3 Main spindles of precision CNC lathes

Suitable for switching between rough turning and finish turning with adjustable bearing preload

4.4 High-precision automated rotary fixtures, heavy-duty indexing spindles

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

SP precision bearings should be assembled inside clean dust-proof workshops. Thoroughly remove contaminants on shaft journals, housing bores, lock nuts and spacer mating surfaces. Preload of 1:12 tapered bore is realized by axial compression with lock nut; direct hammer striking onto bearing face is strictly prohibited. Adjust preload gradually during assembly. Excessive preload causes bearing overheating and seizure. Lubrication channels on housing need to align precisely with outer ring W33 oil holes to guarantee unobstructed oil flow. Reliable sealing must be fitted on bearing housings to block coolant and dust ingress. NN bearing supports radial loads only; axial loads must be undertaken by paired angular contact ball bearings.

5.2 Selection Guidance

24h continuous mass production, on-line re-lubrication required, adjustable on-site preload, high radial rigidity demanded → NN3016 KTN3/SPW33

Continuous operation with fixed preload without adjustment demand → NN3016 TN/SP

Intermittent machining, scheduled downtime lubrication maintenance, priority for high rotational speed → N1016 TN/SP

Mirror finishing requiring superior rotary accuracy → NN3016 KTN3/UPW33

Important notice: Taper bore preload adjustment must comply with spindle manufacturer specifications. Excessive preload leads to rapid temperature rise and shortened service life; insufficient preload reduces rigidity and aggravates machining vibration. Ensure lubrication pipelines align accurately with outer ring oil holes to avoid uneven wear caused by blocked oil supply.

5.3 Lubrication Maintenance Instruction

No lubricant pre-filled at factory. Both grease lubrication and oil-air lubrication are applicable. The W33 design enables continuous lubricant replenishment during equipment operation. Select long-life high-speed lubricant and implement regular on-line lubrication management. Constantly monitor spindle temperature rise and vibration. Inspect lubrication system flow once abnormal heating occurs.

5.4 Environmental Application Notes

Open structure without built-in seals; labyrinth seals or oil seals are mandatory on bearing housings. Raceways and rolling elements are sensitive to hard particulate contaminants. Foreign matter ingress easily results in raceway pitting and permanent accuracy loss. TN3 cage fits standard high-speed working conditions; avoid prolonged exposure to extreme high temperature to slow down cage aging.

6 Fault Identification

Common failure modes: obvious chatter marks on machined workpieces, continuous dimensional drift, excessive temperature rise at high spindle speed, periodic abnormal noise during operation, roller edge scuffing, raceway fatigue spalling. Typical failures for tapered bore bearings: persistent overheating or insufficient rigidity induced by improper preload setting; uneven lubrication caused by misaligned or blocked pipelines; unilateral roller abrasion from unexpected axial loads; raceway scratching due to contaminant penetration via failed seals. Shut down equipment immediately upon accuracy decline, abnormal temperature rise or abnormal noise. Bearings with permanent damage to raceways, rollers or cage cannot be repaired and require complete replacement.