Double Row Cylindrical Roller Bearing NNU4921 B/Sp W33 for Heavy Duty Machinery

Product Specifications

Application Industries

Eliminate Downtime with Reliable NNU4921 B/Sp W33 Double Row Cylindrical Roller Bearings

Equipment failures caused by substandard bearings cost manufacturers thousands in lost production each year. When bearings fail prematurely in heavy duty machinery, the resulting downtime disrupts schedules, increases maintenance costs, and damages critical equipment components. Sourcing genuine, high-precision bearings that meet exact specifications remains a persistent challenge for industrial buyers.

Engineered for Heavy Load Applications in Demanding Environments

The NNU4921 B/Sp W33 double row cylindrical roller bearing delivers exceptional performance in heavy duty machinery operating under high radial loads. With decades of manufacturing experience, we produce these bearings to P0-P4 precision grades and Z2-Z4 noise standards, ensuring compatibility with industrial equipment requiring reliable rotation under extreme conditions. Our one-stop service integrates independent R&D and strict quality control, providing bearings that maintain stability in gearboxes, rolling mills, and construction machinery.

Optimal Performance in High-Stress Industrial Conditions

This double row cylindrical roller bearing excels in applications involving heavy radial loads and moderate axial loads, common in industrial gearboxes and large electric motors. Its separated design allows for easy mounting and dismounting, simplifying maintenance procedures. The W33 designation indicates a cylindrical outer ring with lubrication grooves and holes, ensuring efficient lubricant distribution even at high operating temperatures. When paired with proper lubrication, this bearing maintains performance in environments with continuous operation and variable load conditions.

Technical Features That Ensure Long Service Life

The bearing’s 60-64 HRC hardness provides exceptional wear resistance, critical for extending service life in abrasive environments. Available radial clearances (C0-C5) allow precise matching to specific operating conditions—tighter clearances (C2) for high-precision applications like CNC spindles, while larger clearances (C4-C5) accommodate thermal expansion in high-temperature equipment. Brass and steel cage options offer distinct advantages: brass cages provide superior strength for shock-loaded applications, while steel cages optimize performance in high-speed rotating equipment. Vibration grades Z1V1 to Z3V3 ensure smooth operation, reducing noise and minimizing equipment fatigue.

Total Cost of Ownership: Why Quality Matters More Than Price

Choosing lower-quality bearings may reduce initial costs, but frequently leads to higher long-term expenses. Counterfeit bearings often fail within 30-50% of the expected service life, requiring unplanned maintenance and production stoppages. Our NNU4921 B/Sp W33 bearings meet ISO, ABMA, and DIN international standards, ensuring consistent performance and predictable service intervals. Each bearing undergoes dimensional inspection and vibration testing in our in-house laboratory, verifying compliance with strict quality criteria. The result is a heavy duty machinery bearing that delivers reliable performance, reducing total ownership costs through extended service life and minimized downtime.

Our Commitment to Reliable Bearing Solutions

Packaging & Shipping

• Secure carton packaging with pallet reinforcement for bulk orders
• Sample orders shipped within 3-5 working days
• Bulk orders delivered in 5-15 working days
• Multiple logistics options including DHL, FedEx, UPS, air, and sea freight
• Real-time tracking provided for all shipments
• 1 piece minimum order quantity available for emergency replacement

Get Your NNU4921 B/Sp W33 Bearing Today

Don’t let equipment downtime impact your production schedule. Contact us with your bearing requirements, application details, and quantity needs to receive a prompt quotation. Our inventory includes standard configurations for immediate shipment, ensuring you can resume operations with minimal delay.

Frequently Asked Questions