Deep groove ball bearings are the most versatile rolling bearings on the market, featuring a single-row steel ball and curved deep groove raceway structure with compact and simple design. They bear radial loads as well as slight bidirectional axial loads with outstanding limiting speed and smooth low-noise operation. Four sealing types are available: open type, single-side metal shield Z, double-side metal shield ZZ, double-side rubber seal 2RS, adapting to long-term grease sealing and oil bath lubrication. They serve as standard bearings for three-phase asynchronous motors, cooling fans, water pumps, air compressor heads, household appliances, conveyor rollers, small reducers and hardware machinery.

Main model classification: 6000 ultra-thin light-duty series, 6200 standard mainstream series, 6300 thickened heavy-duty series, derivative 6400 extra heavy-duty, 618/619 thin-wall ultra-thin series. Sealing options: OPEN open type (oil bath lubrication), Z/ZZ steel dust shield (dry dust-free environment), 2RS double rubber seal (waterproof, dustproof, grease leakage prevention).

Compared with roller bearings, they feature compact size, easy assembly, cost advantages and superior high-speed mute performance. Different from angular contact ball bearings requiring paired installation, a single bearing withstands combined radial and axial force to adapt to minor axial float of conventional rotating shafts. The main disadvantage is weaker impact resistance under heavy load than roller bearings, unsuitable for heavy impact equipment such as mine crushers and rolling mills, only for stable medium & light-load transmission.

Civil electromechanical equipment, industrial fans & water pumps and kitchen appliances run continuously under humid moisture, floating dust and long-term grease aging. Inferior deep groove ball bearings suffer poor steel ball roundness and rough raceway grinding texture, resulting in persistent howling noise at high speed. Low-quality rubber seals crack rapidly when exposed to water and oil, allowing moisture and dust to corrode steel balls and form pits on raceways. Loose riveted cages cause collision noise under high-speed centrifugal swing, enlarged bearing clearance and seizure. Consequences include abnormal motor noise & overheating, fan vibration, pump jamming caused by water & dust ingress and household appliance stalling, leading to frequent equipment rework and rising maintenance costs.

NMT deep groove ball bearings cover full specifications of 6000, 6200, 6300, 6400, 618 and 619 series with complete open, ZZ metal shield and 2RS rubber seal configurations, plus optional C3 clearance for dedicated motors. Bearings are made of refined high-carbon chromium bearing steel. Super mirror finishing grinding is applied on inner and outer ring raceways. High-precision G5 grade steel balls are grouped by size to guarantee rotational concentricity. Integral stamping and riveting reinforcement on cages eliminate looseness under high speed. 2RS seals adopt oil & water resistant nitrile rubber with tight lip fitting for excellent waterproof, dustproof and grease retention performance. Standard international dimensions support direct replacement of imported and domestic deep groove ball bearings for complete machine assembly, motor maintenance, home appliance repair and fan & pump parts replacement.

Small industrial electromechanical products, kitchen & bathroom appliances and vehicle-mounted fans are upgraded toward mute operation, long service life and maintenance-free performance. Conventional deep groove ball bearings feature low precision, poor weather resistance of seals and easy grease loss, causing sharp noise rise and rust failure after water ingress in long-term use, failing to meet demands of mute fan operation, moisture-proof durable pumps and long-term maintenance-free household appliances. The market demands high-precision mute deep groove ball bearings with durable sealing performance.

NMT deep groove raceways adopt superfinishing grinding for smooth curved surfaces to minimize rolling friction of steel balls and reduce high-speed operating noise. Grouped high-precision steel balls realize even circumferential load distribution to avoid wear from local stress concentration. Flexible sealing selection: open type for gearbox oil bath lubrication, ZZ metal shield for indoor dry fans, 2RS double rubber seal for water pumps, outdoor fans and humid dusty conditions. Pre-filled long-life composite grease resists caking and leakage under high & low temperatures to extend maintenance-free cycles. C3 large clearance models are customized for motor high-temperature operation to compensate shaft thermal expansion and prevent bearing seizure from overheating.

All finished bearings pass decibel noise test, high-speed endurance aging test, waterproof & dustproof sealing test and rotational concentricity inspection to eliminate defective products with abnormal noise, out-of-roundness and poor sealing, ensuring stable low-noise long-term operation of general machinery equipment.

Core Product Advantages

Classic deep groove structure bears radial and bidirectional axial loads simultaneously for composite force conditions of conventional rotating shafts.

Super mirror raceway + precision steel balls deliver smooth rotation, low noise and slight vibration at high speed.

Three sealing structures for selection: metal shield for dust prevention in dry environment, rubber seal for waterproof and grease locking in humid dusty scenarios.

Integral reinforced stamped cages resist loosening and deformation under high-speed rotation for strong operational stability.

Optional C3 clearance dedicated for motors adapts to motor temperature rise expansion to avoid overheating seizure failure.

Pre-filled long-life lubricating grease enables long-term maintenance-free operation for 2RS sealed bearings without grease refilling.

Universal standard dimensions support direct interchange for most small rotating shafts in the market.

Full product coverage from thin-wall light-duty to thickened medium heavy-duty for household small appliances and medium industrial water pumps.

Typical Application Scenarios

Main shafts of industrial three-phase motors, variable-frequency motors, fan motors, cooling tower fans and centrifugal fans; bearings for clean water centrifugal pumps, circulating water pumps, booster pumps and small air compressor spindles; home appliances including range hoods, washing machines, outdoor air conditioning units, blenders and electric fans; assembly line rollers, conveyor idlers and small gear reduction boxes; power tools, garden machinery, air compressors and refrigeration compressor parts; automotive blowers, generators and auxiliary bearings for small ships & vehicles.

Quality Assurance

NMT deep groove ball bearings adopt high-purity GCr15 bearing steel with overall quenching and tempering for uniform hardness, improved rust resistance and contact fatigue resistance. Double superfinishing on raceways eliminates machining texture to reduce rolling friction noise. Steel balls are strictly graded with roundness error controlled at micron level. Rubber seals use aging-resistant NBR rubber with resistance to high & low temperatures and lubricant corrosion. Cold-rolled steel stamping for dust shields with folded edge compression for reliable dust blocking. Bearings are classified into standard clearance and C3 motor clearance before delivery. Special clearance optimization for high-temperature motor equipment suppresses operating temperature rise. The bearings are fully applicable to general machinery conditions including normal temperature, humidity, light dust and continuous high-speed rotation.

Product Range

6000 thin-wall light-duty, 6200 standard general-purpose, 6300 thickened heavy-duty, 6400 extra heavy-duty, 618/619 ultra-thin-wall deep groove ball bearings; OPEN open type, ZZ double-sided metal dust shield, 2RS double-sided rubber seal; standard clearance, C3 large clearance for motors.

Brand Strength

NMT Japan addresses three common defects of ordinary deep groove ball bearings: loud noise caused by rough raceways, rust failure from water & dust ingress due to seal aging, abnormal noise from loose cages at high speed. Process upgrades including mirror superfinishing on raceways, matched high-precision steel balls and composite durable seals enhance bearing mute performance, sealing protection and service life. We supply cost-effective general bearings for motor manufacturers, fan & pump producers, home appliance component factories and hardware traders to reduce failures such as excessive noise, rust seizure and frequent part replacement of electromechanical equipment, cutting comprehensive equipment maintenance costs.