6801 LLU/5K NTN Ball Bearing 12x21x5

Design and Construction

6801 LLU/5K NTN is a slim section deep groove ball bearing designed for compact assemblies where axial space is limited but reliable rotational performance is required.

This model strengthens the NTN ball bearings category as part of the 6800 thin series, widely used in precision mechanical systems. With dimensions 12x21x5 mm, it offers a reduced cross section compared to standard 6000 series bearings, making it suitable for lightweight and space optimized designs.

The LLU designation indicates double sided contact rubber seals. These seals provide enhanced protection against dust, moisture and fine contaminants, while retaining lubricant inside the bearing. The internal geometry of the raceways ensures smooth ball guidance and stable operation at moderate to high rotational speeds.

The 5K specification refers to NTN production standard, ensuring dimensional consistency and controlled manufacturing quality required in B2B and OEM environments.

Technical Parameters

Technical data of 6801 LLU/5K NTN:

• Type: single row deep groove ball bearing, thin section

• Bore diameter d: 12 mm

• Outside diameter D: 21 mm

• Width B: 5 mm

• Sealing: LLU double contact rubber seals

• Manufacturer: NTN

Technical snippet ready section:
6801 LLU/5K NTN is a 12x21x5 mm thin section deep groove ball bearing with double contact seals LLU, designed for compact and well protected rotating systems.

Long tail dimensional phrases include: 12x21x5 NTN bearing, 6801 LLU thin ball bearing, slim deep groove ball bearing 6801.

Industrial Applications

The 6801 LLU/5K NTN deep groove ball bearing is commonly used in:

• electric bike drive systems

• compact electric motors

• lightweight gear units

• laboratory and medical devices

• robotics and automation modules

In industrial B2B applications, the 12x21x5 ball bearing is selected when designers need to reduce housing width and overall system weight without compromising rotational accuracy. The contact seals LLU make it suitable for environments exposed to moisture or fine particles.

Operational Advantages

Compared to open or metal shielded versions, 6801 LLU/5K NTN offers:

• improved sealing performance

• better protection against contamination

• reduced lubricant leakage

• stable operation in variable load conditions

Within the NTN ball bearings portfolio, the 6801 LLU/5K model represents the thin section solution for compact mechanical assemblies requiring enhanced sealing and dimensional precision.

Main Description

The 6801 LLU/5K NTN deep groove ball bearing 12x21x5 mm is a thin section single row bearing with double contact seals, engineered for compact industrial and OEM applications.

With a bore diameter of 12 mm, outside diameter of 21 mm and width of only 5 mm, this bearing fits into designs where standard width bearings cannot be installed. The slim 12x21x5 configuration allows engineers to optimize axial space and reduce total assembly weight.

The LLU contact seals provide effective protection of the raceway and rolling elements. In practical industrial use, this translates into extended service life in equipment operating in dusty or humid environments. Typical applications include electric bike hubs, small drive motors, precision instruments and automation components.

For OEM manufacturers and maintenance departments, NTN ball bearings are recognized for consistent tolerances and reliable performance. The 6801 LLU/5K NTN model integrates into the broader NTN ball bearing range, covering thin section, shielded and sealed variants for diverse operational requirements.

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FAQ

1. Is 6801 LLU/5K NTN suitable for electric bike applications?
   Yes, the slim 12x21x5 design and LLU contact seals make it well suited for e bike drive systems.

2. What is the difference between LLU and ZZ sealing?
   LLU are contact rubber seals providing higher protection, while ZZ are metal shields with lower friction but reduced sealing.

3. Is the 6801 LLU/5K bearing pre lubricated?
   Yes, it is factory lubricated and ready for installation.

4. Why choose a thin section 6801 instead of 6001?
   The 6801 series has a smaller width, allowing installation in space constrained designs.