1. Product Introduction

The 6301-ZZ is a single-row deep groove ball bearing of 12 × 37 × 12 mm with a stainless steel shield pressed on both sides. The shields are non-contact: they sit in the outer ring groove with a small labyrinth gap and never touch the inner ring, so they stop dust, grit and chips from reaching the raceway while adding almost no friction. Inside, GCr15 chrome bearing steel rings and balls are hardened to HRC 60-62 and ground to P5 (ABEC-5) precision, delivering Z4 noise and V4 vibration behaviour. The bearing is filled with lithium base grease for life, so it runs maintenance-free in dry, dusty workshops where a rubber lip would run hot but an open bearing would be destroyed by contamination.

2. Product Features

• Non-contact metal shields: the two pressed steel shields close the ball path against dust and metal particles through a narrow labyrinth gap without rubbing, so protection comes with very little extra torque.
• Cooler running than a lip seal: because there is no friction between shield and inner ring, the bearing tolerates higher speed and produces a smaller temperature rise in continuous operation.
• P5 precision grade: tight bore and outside diameter tolerance, low run-out and consistent fits keep vibration low in gearbox and motor seats.
• Z4 noise, V4 vibration: superfinished grooves and closely graded balls give the quietest running class in the range, which matters when the bearing sits close to an operator.
• Grease retained for life: the shields keep the factory grease in place and stop dust from thickening it, so no relubrication point is needed on the machine.
• High load in a small envelope: 9.72 kN dynamic and 5.08 kN static rating in a 12 mm bore bearing supports both radial load and moderate axial load in either direction.
• Direct replacement: the 12 × 37 × 12 mm dimensions follow the international 6301 series, so ZZ, 2Z and open versions of the same size interchange in one seat.

3. Product Advantages

Every 6301-ZZ bearing is inspected on roundness, hardness, noise, vibration and shield tightness before it leaves the line, so a full container arrives with the same running quality as the first sample. The shielded design removes the maintenance step from the customer side: there is no grease nipple to service and no seal to replace, which lowers the total cost of ownership for OEMs that build sealed-for-life assemblies. Compared with a rubber sealed bearing of the same size the shielded version turns more freely and heats up less, while still surviving dusty plant air. Factory-direct production supports P6 or P5 grades, selected clearance, quiet-running ball grading and neutral packaging, and the 6301 size is held in stock for fast delivery.

4. Product Technical Parameters

5. Product Applications

The typical application of the 6301-ZZ is the gearbox of an electric chain hoist. A hoist works in a workshop or on a construction site where abrasive dust, grit from the floor and metal particles from welding are always in the air, and the gearbox shaft bearing is the part that fails first when contamination gets in. The non-contact steel shields stop that dust at the gap, keep the factory grease clean and let the shaft keep turning at full hoist speed without the drag and heat of a rubber lip. Because the shield does not rub, the bearing also survives the frequent start and stop cycles of a lifting duty without wearing a groove into the seal.

The same shielded bearing is used in dusty gearmotor and reducer shafts, fan and blower motor seats, conveyor drive rollers, packing machine cam shafts, small agricultural implement drives and general industrial transmission positions where protection from dirt is needed without losing speed capability.

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.