Double Row Deep Groove Ball Bearings

BMT Bearings' Double Row Deep Groove Ball Bearings are used where a single row bearing cannot handle the load. With two rows of balls instead of one, these bearings deliver significantly higher load capacity while keeping the same bore and outside diameter as their single-row counterparts. gaining a considerable in load capacity, about 1.6 times the radial capacity of a single-row bearing, exhibiting robust operation, little maintenance, higher running speeds.

Core Advantages

Higher load capacity

The double-row layout directly doubles load-carrying capability and can increase the load of the equipment.

Bidirectional axial load capacity

The deep groove design creates a high degree of conformity between the balls and the raceways, which allows these bearings to carry axial loads from both directions.

Low maintenance and long service life

BMT Bearings uses high-quality bearing steel and optimized heat treatment to improve wear resistance under continuous operation. The bearings are robust and require little maintenance in service. Combined with proper lubrication and installation, they deliver long, reliable service.

High-speed capability

Double Row Deep Groove Ball Bearings maintain low friction and can run at high speeds. The open design allows for effective heat dissipation, supporting higher operating temperatures.

Structural Design Features

Two rows, two grooves

Both the inner and outer rings have two parallel raceway grooves, each holding one row of balls. This doubles the contact area between the rolling elements and the raceways compared to a single-row bearing.

Deep groove geometry

The raceway grooves are deeper than those in other bearing types, creating a tight fit between the balls and the raceways. This close conformity is what enables the bearing to handle axial loads in both directions. It also contributes to smooth, quiet operation.

Product Parameters

 

Installation and Safe Mounting

1. Before installation: Clean the bearing with gasoline or kerosene and dry it. Ensure the shaft and housing are clean, burr-free, and within tolerance.

2. Press-fit: Use a press to mount the bearing. Apply force evenly on the ring face only on the ring being mounted. Never use a hammer.

3. Heat-fit: For larger bearings or tighter fits, heat the bearing evenly (do not use an open flame) or cool the shaft.

4. After installation: Rotate the bearing by hand to check for smooth, free movement. Confirm the inner ring seats fully against the shaft shoulder and the outer ring against the housing shoulder.

5. Lubrication : Grease is the standard choice; oil is also acceptable. For bearings supplied without grease, apply the recommended lubricant before installation.

Applications

Our Double Row Deep Groove Ball Bearings are used across a wide range of industries:

Automotive: Wheel hub units, gearbox shafts, alternator pulleys

Industrial machinery: Machine tool spindles, conveyor rollers, pumps and compressors

Electric motors: High-efficiency motors (IE3/IE4 rated)

Agricultural equipment and construction machinery: Gearboxes, heavy equipment

Manufacturing Process

Bearing Steel Selection

BMT Bearings uses high-quality bearing steel with controlled chemical composition to improve fatigue resistance and dimensional stability during long-term operation.

Heat Treatment

Through optimized heat treatment processes, the bearing rings achieve suitable hardness and toughness, helping reduce deformation and improve wear resistance.

Precision Grinding

Advanced grinding equipment ensures accurate raceway geometry, surface finish, and dimensional consistency for smooth rotation and reduced friction.

Assembly and Inspection

Each bearing is inspected for dimensional accuracy, rotation performance, noise level, and appearance before shipment.

FAQ

Q1: What is the difference between a Double Row Deep Groove Ball Bearing and a single-row bearing?

The main difference is load capacity and width. Double Row Deep Groove Ball Bearings have two rows of balls instead of one, giving them roughly 1.6 times the radial load capacity of a single-row bearing with the same bore and outside diameter. They are slightly wider, so they require more space in the axial direction, but they deliver considerably higher load capacity in the same radial envelope.

Q2: Can Double Row Deep Groove Ball Bearings handle axial loads?

Yes. The deep groove design allows these bearings to carry axial loads from both directions. For pure axial loading, keep the axial load below 0.5 times the static load rating (0.5 Co). If the axial load exceeds this, consider a different bearing type or consult the manufacturer.

Q3: Do Double Row Deep Groove Ball Bearings require preload?

Double Row Deep Groove Ball Bearings are preloaded at the factory before shipment. In most standard applications (electric motors, agricultural equipment, wheel hubs), the bearings are delivered with the correct radial clearance (CN) and do not require additional preloading. Over-preloading can cause overheating and premature failure.

Q4: How should I install a Double Row Deep Groove Ball Bearing?

Clean the bearing before installation. Use a press to mount the bearing, applying pressure evenly around the ring face. Never strike the bearing directly with a hammer. After installation, rotate the bearing by hand to check for smooth, free rotation. For detailed guidance, contact our technicians.

Q5: What is the "A" in 4200A and 4300A series?

The "A" indicates a design without a ball loading notch. This allows the bearing to have a higher number of balls, which increases load capacity compared to designs with a loading notch. The cages are inserted from each side of the bearing during assembly.

Why Choose BMT Bearings?

Dual quality certifications

BMT Bearings holds both ISO 9001 and IATF 16949 certifications, every bearing is produced under automotive-grade quality control making sure consistent quality.

Large-scale manufacturing capacity

With over 100 automatic grinding and assembly lines and an annual output of 100 million pieces, BMT Bearings has the capacity to handle both small trial orders and large-volume production runs.

Export experience

We exports to countries and regions worldwide with over 20 years of expertise. Familiarity with different markets' packaging, shipping, and customs requirements means smoother delivery.

Full-cycle service

From technical consultation, custom design to sample confirmation, production follow-up, and after-sales support, we provides dedicated support throughout the entire process.