NMT Ltd.
Corporate Communications Department
Japan NMT N 1012 KTN/SP Super-Precision Single Row Cylindrical Roller Bearing – The Outstanding Choice for High-Speed High-Precision Spindles
1 Model Information & Technical Parameters
Model:N 1012 KTN/SP
Basic Dimensions
Parameter Value Unit
Bore diameter (d) 60 mm
Outside diameter (D) 95 mm
Width (B) 18 mm
Inner ring flange diameter (d₁) 73.3 mm
Outer ring raceway diameter (E) 86.1 mm
Chamfer dimension (r₁,₂ min.) 1.1 mm
Chamfer dimension (r₃,₄ min.) 0.6 mm
Permissible axial displacement (s max.) 2.5 mm
Bore diameter tolerance 0 to +0.015 mm
Outside diameter tolerance -0.010 to 0 mm
Width tolerance -0.15 to 0 mm
Bore type Tapered 1:12 —
Accuracy class SP (Super Precision) —
Radial internal clearance C1 —
Performance Data
Parameter Value Unit
Dynamic load rating (C) 42.9 kN
Static load rating (C₀) 53 kN
Fatigue load limit (Pᵤ) 6.3 kN
Reference speed 11,000 r/min
Limiting speed – grease 11,000 r/min
Limiting speed – oil-air 12,000 r/min
Axial static stiffness (guideline) 680 N/µm
Reference grease quantity 4.7 cm³
Operating temperature range -30 ~ +110 °C
Radial clearance C1 —
Technical Attributes
Attribute Detail
Bearing type Super-precision single row cylindrical roller bearing
Series N 10
Number of rows 1
Inner ring design Two flanges (integral ribs)
Outer ring design Flangeless
Cage material PA66 nylon injection moulded cage, roller centred
Roller material Chrome steel
Ring material Chrome steel
Seal type Open (no seals)
Bore type Tapered 1:12
Accuracy class SP (dimensional accuracy approx. P5, running accuracy approx. P4)
Radial clearance C1
Separable design Yes (inner and outer rings separable)
Design speed High
Logistics & Industry Codes
Parameter Value Unit
Net weight 0.413 kg
Indicative carbon footprint 1.5 kg CO₂e
eClass code 23-05-09-01 —
UNSPSC code 31171505 —
Suffix Full Explanation
Suffix Meaning
N Single row cylindrical roller bearing, two flanges on inner ring, flangeless outer ring
10 Dimension series (N10 series)
12 Bore size code – 60 mm (12 × 5 = 60 mm)
K Tapered bore, taper 1:12
TN PA66 nylon injection moulded cage, roller centred
SP Super Precision class – dimensional accuracy approx. ISO 5, running accuracy approx. ISO 4
Important reminder: This model features a tapered bore (1:12) . During mounting, a lock nut or hydraulic nut is used to drive the bearing onto the tapered shaft journal, enabling precise adjustment of radial clearance. The bearing is open-type without seals and requires external lubrication and sealing protection based on actual operating conditions. Operating temperature range: -30°C to +110°C. The separable design allows independent mounting of inner and outer rings. The SP accuracy class (dimensional accuracy approx. P5, running accuracy approx. P4) ensures extremely high running accuracy. The two-flange inner ring and flangeless outer ring (N-type) allow the bearing to accommodate axial displacement in both directions (max. 2.5 mm), effectively compensating for thermal expansion. This bearing type is commonly used as a floating bearing.
2 Structure & Operating Characteristics
The NMT N 1012 KTN/SP is a super-precision single row cylindrical roller bearing (N-type) , specifically developed for high-speed, high-precision spindle applications. This bearing achieves an excellent balance between load capacity, speed and accuracy.
Single row roller design is the structural foundation. Single row cylindrical rollers with line contact between rollers and raceways provide high radial load capacity (dynamic load 42.9 kN, static load 53 kN) and low friction characteristics. Compared to full-complement cylindrical roller bearings, the caged design allows higher speeds with less frictional heat generation, making it particularly suitable for high-speed rotation (oil-air limiting speed up to 12,000 r/min).
Two-flange inner ring and flangeless outer ring (N-type design) allow the bearing to accommodate axial displacement in both directions, with maximum permissible axial displacement of 2.5 mm, effectively compensating for thermal expansion. The bearing itself does not carry axial loads; axial displacement is accommodated by the external structure. Therefore, N-type bearings are commonly used as floating bearings.
PA66 nylon injection moulded cage (TN suffix) is a key technological feature. PA66 (nylon 66) material offers excellent wear resistance and low friction characteristics, effectively reducing heat generation and energy consumption. The cage ensures precise roller positioning and stability at high speeds, preventing cylindrical rollers from contacting each other and enabling controlled motion of rolling elements.
Tapered bore (1:12) design enables precise radial clearance adjustment through axial advancement during mounting, critical for optimizing spindle system rigidity and accuracy.
SP Super Precision class is the hallmark of NMT super-precision bearings – dimensional accuracy approx. ISO 5, running accuracy approx. ISO 4 – ensuring extremely high running accuracy and low vibration levels.
3 Core Performance Advantages
1. Perfect balance of high radial load capacity and low friction. Single row cylindrical roller line contact structure provides high radial load capacity (dynamic load 42.9 kN, static load 53 kN) while maintaining low friction characteristics, suitable for high-speed rotation.
2. PA66 nylon cage (TN) – stability at high speeds. PA66 material offers excellent wear resistance and low friction characteristics. The cage ensures precise roller positioning and stability at high speeds, effectively reducing friction and heat generation.
3. Super-precision running accuracy (SP). Dimensional accuracy approx. ISO 5, running accuracy approx. ISO 4, ensuring ultra-low vibration, ultra-low noise and ultra-low heat generation to meet high-precision machining requirements.
4. Bidirectional axial displacement compensation (max. 2.5 mm). The two-flange inner ring and flangeless outer ring design allow the bearing to accommodate axial displacement in both directions during operation, with maximum permissible axial displacement of 2.5 mm, effectively compensating for thermal expansion. This bearing is commonly used as a floating bearing.
5. Tapered bore mounting with precisely adjustable clearance. 1:12 tapered bore enables precise radial clearance adjustment through axial advancement during mounting, optimizing system rigidity.
6. Separable design for easy assembly and maintenance. Inner and outer rings can be mounted independently, greatly simplifying assembly and disassembly.
7. Excellent high-speed performance. Grease limiting speed: 11,000 r/min; oil-air limiting speed: 12,000 r/min, meeting high-speed spindle requirements.
4 Typical Application Fields
This bearing is suitable for large and medium electric motors, rolling stock, machine tool spindles, internal combustion engines, generators, gas turbines, gearboxes, rolling mills, vibrating screens, and lifting and transport machinery.
4.1 High-Speed Machine Tool Spindles
High-speed machining center spindles, high-speed milling spindles, high-speed grinding spindles – the combination of high precision and high speed is a perfect match.
4.2 Precision Grinding Machines
External cylindrical grinder spindles, internal grinder spindles – high radial load capacity and running accuracy ensure machining quality.
4.3 Aerospace Engines and Gas Turbines
Aircraft engine main shafts, gas turbine rotor supports – high strength and reliability meet aerospace requirements.
4.4 High-Performance Automotive and Racing
High-performance automotive transmissions, racing gearboxes, high-speed drive units.
4.5 Electric Motors and Generators
Large and medium electric motors, generators – stable performance under heavy loads and high speeds.
4.6 Industrial Machinery and Automation
Gearboxes, rolling mills, vibrating screens, lifting and transport machinery; robotics and automation system rotary supports.
4.7 Medical Equipment
Advanced imaging equipment rotating components – high precision ensures equipment reliability.
5 Assembly Specifications & Usage Guidelines
5.1 Pre-installation Inspection
Verify model and specifications match design requirements. Inspect bearing appearance to ensure no damage, corrosion or foreign matter. Check shaft taper (1:12) and dimensional accuracy against design specifications. Prepare appropriate mounting tools such as lock nuts or hydraulic nuts.
5.2 Installation Procedure
This bearing features a tapered bore (1:12) . During mounting, the bearing must be driven onto the tapered shaft journal. Use a lock nut or hydraulic nut to apply axial advancement force, precisely adjusting radial clearance by controlling advancement distance. Never apply force through rolling elements or cage. Monitor radial clearance changes throughout installation until the target clearance value (corresponding to C1 clearance class) is achieved. The separable design allows independent mounting of inner and outer rings. Recommended shaft abutment minimum diameter is 66.5 mm; housing abutment minimum diameter is 87 mm, maximum is 88.5 mm.
5.3 Clearance Adjustment Instructions
Radial clearance of tapered bore bearings decreases as axial advancement increases. During mounting, use feeler gauges or dial indicators to monitor clearance changes, ensuring clearance is adjusted to the design target. Maximum permissible axial displacement is 2.5 mm – sufficient axial clearance must be预留 in the design.
5.4 Lubrication Maintenance
This model comes without pre-filled grease – lubricant must be added during installation based on operating conditions. Grease limiting speed is 11,000 r/min; oil-air limiting speed is 12,000 r/min. Reference grease quantity is 4.7 cm³. High-quality synthetic grease or specialized high-speed spindle oil is recommended. Open construction requires reliable sealing protection at the equipment level. Establish regular lubrication replenishment schedule; dry running is strictly forbidden.
5.5 Environmental Considerations
Operating temperature range: -30°C to +110°C. As this bearing is open construction, in dusty environments or coolant splash conditions, labyrinth seals or contact seals must be provided at the equipment level. The bearing itself does not carry axial loads; axial displacement (max. 2.5 mm) is accommodated by the external structure.
6 Fault Identification
Common failure modes: Roller or raceway fatigue pitting, abnormal operating noise increase, significant rotation resistance increase, excessive temperature rise, seizure caused by poor lubrication. If cage deformation or rolling element damage occurs, replace the entire bearing assembly – repair and reuse are not allowed. Regularly monitor bearing temperature and vibration for early detection of abnormalities.