1. Product Introduction

The 6302-ZZ is a single-row deep groove ball bearing with a 15 mm bore, 42 mm outside diameter and 13 mm width, closed on both sides by pressed steel ZZ shields. Rings and balls are ground from GCr15 chrome bearing steel, graded in matched sets and assembled to P6 (ABEC-3) tolerance with Z3V3 noise and vibration control, so the unit turns quietly at high speed with very little extra drag. Because the shields are non-contact, grease circulates freely inside the raceway and no seal lip rubs on the inner ring, which keeps friction torque and running temperature low during long high-speed shifts. The standard ISO boundary dimensions of 15 × 42 × 13 mm let the bearing replace an existing 6302 position directly, without machining shafts or housings.

The combination of speed capability, stable low noise and effective dust shielding makes the 6302-ZZ a practical shaft support for sewing machine servo motors, where the rotor shaft runs continuously and lint, thread fibre and cutting dust must be kept away from the rolling elements.

2. Product Features

• Non-contact ZZ shields: two pressed steel shields close both sides of the bearing and stop lint, fibre, dust and chips from reaching the raceway, while the small internal gap keeps grease flow and heat dissipation intact.
• Z3V3 quiet running: raceways are superfinished and balls are sorted by diameter before matching, holding noise and vibration to the Z3V3 grade for steady, low-sound operation.
• P6 dimensional accuracy: controlled bore, outside diameter and roundness tolerances give a firm interference fit on the shaft, low run-out and repeatable mounting position from batch to batch.
• Speed-ready internal design: low-friction shielded construction allows grease lubrication up to 13,000 r/min, so the bearing follows high-speed motor rotors without overheating.
• Combined load capacity: the deep groove geometry accepts radial load together with moderate axial load in both directions, covering belt pull and rotor thrust in one component.
• Wear resistance: through-hardened GCr15 steel delivers high surface hardness and fatigue strength, so the bearing holds its clearance and noise level over a long service period.
• Direct interchangeability: 15 × 42 × 13 mm ISO dimensions match the standard 6302 envelope, simplifying stock keeping and after-sales replacement.

3. Product Advantages

Each 6302-ZZ batch is checked at four stages — incoming steel, grinding, assembly and finished goods — on bore size, raceway roundness, hardness, noise and vibration, so the parts that leave the line behave the same way in the customer's motor. The shielded structure needs no relubrication in normal service, which trims maintenance work on high-speed production equipment, and the steel shields resist the fine dust found in sewing rooms better than open bearings. Factory-direct supply covers customized precision grade, clearance, grease and neutral packing, with regular stock of the 6302 section available for short lead times.

4. Product Technical Parameters

5. Product Applications

The most typical duty of the 6302-ZZ is the shaft support of a sewing machine servo motor: the bearing sits at the rotor shaft of the servo motor that drives the main shaft of an industrial lockstitch or overlock machine, turning at high speed through long shifts while thread fibre and fabric dust fill the air around the machine head. The non-contact steel shields keep that debris out of the raceway and the Z3V3 noise level keeps the motor quiet enough for a crowded sewing workshop.

Further installations include servo and stepper motor end shields of automated sewing and embroidery units, copier and printer drive rollers, small axial cooling fans, electric power tool gearboxes, vacuum cleaner motor shafts and textile winding machine spindles.

6. Company Profile

Ningbo Kent Bearing Company was established in 2003 and is one of the leading bearing manufacturers and exporters in China. Kent specializes in the design and production of high precision, high speed and low noise deep groove ball bearings and pillow block bearings. At present, the Corporation has more than 1,000 employees, a fixed assets of 2 billion yuan, and produces 250 million sets of bearings annually. The Corporation's products are widely used in more than 50 countries and regions under 2 independent brands, namely "BUGAO" and "NBKT".

Since 2003, the Corporation has set up a Research & Development Center equipped with multiple laboratories used for precision measurement, mechanical testing, lifespan testing, and physicochemical testing, to continuously upgrade its skills and raise its manufacturing standard and product's precision. Our workshops are installed with a series of advanced numerically-controlled, grinding and assembly equipment that utilize centralized filtration and cooling systems. Together with the production equipment suppliers, we developed these grinding, ultra-precision, fully automated integrated production lines, and own the intellectual property rights. The precision level of the products are at P5 level and above, with noise level reaching Z4, V4 and above. Some of our projects have exceeded the 30% precision reserves. Our products are widely used in electric motors, automobiles, motorcycles, household appliances, textile, electric tools and water pump equipment industries, both locally and globally.

The company has more than 20 assembly lines, and through ISO9001:2015 quality management system certification, has a professional technical and service team, technical personnel proportion of more than 30%. Over the years, we have been adhering to the use of high-end raw material production, from the first to every step, with excellent product development capabilities and strict quality control, we continue to expand the product line and application range.