6208 Deep Groove Ball Bearing 40x80x18mm

The 6208 bearing is the first 40mm-bore bearing in the 6200 heavy series — the size where industrial electric motors, medium-duty pump shafts, and general-purpose gearboxes converge. At 80mm OD and 18mm width, it carries 29.1 kN dynamic load with nine 12.7mm (1/2-inch) balls, spanning IEC frame 160 through 180 motors from 11 kW to 15 kW. The step up from the 6207 bearing where shaft diameter crosses the 40mm threshold — a common shaft size for industrial pump impellers, belt-conveyor drive pulleys, and air-compressor crankshafts. GCr15 bearing steel, ABEC-1 or ABEC-3 precision, and three sealing configurations.

Key Specifications

Sealing: Open, ZZ metal-shielded, or 2RS double rubber-sealed configurations. ZZ shields maintain 8,600 RPM without friction penalty. 2RS nitrile seals for wet, washdown, or outdoor industrial environments at 5,600 RPM.

Speed and Load: 8,600 RPM in open and ZZ configurations; 5,600 RPM in 2RS sealed. 29.1 kN dynamic load (Cr) and 17.8 kN static load (Cor) at standard CN clearance. Nine 12.7mm balls per row — the first use of 1/2-inch ball diameter in the 6200 series.

Material and Precision: Rings and balls in GCr15 bearing steel (AISI 52100 equivalent), through-hardened to HRC 60–64. Standard ABEC-1 and ABEC-3 precision grades. 100% dimensional inspection with batch-traceable reports.

Operating Direction: Single-row deep groove geometry absorbs combined radial and bidirectional axial loads. Axial capacity approximately 25 percent of radial dynamic rating — adequate for locating bearing duty on industrial pump, compressor, and conveyor drive shafts.

Temperature Range: Standard polyurea grease rated -20°C to 120°C continuous. High-temperature synthetic grease and FKM seal options to 180°C for OEM orders.

For any inquiries, please contact with our Supporting Team at sales@yuanhecd.com.

6208 Deep Groove Ball Bearing 40x80x18mm

Engineering Drawing
Model 6208
Type Open / ZZ Shielded / 2RS Sealed
Bore (d) 40 mm
OD (D) 80 mm
Width (B) 18 mm
Dynamic Load Cr 29.1 kN
Static Load Cor 17.8 kN
Max Speed 8,600 RPM (Open/ZZ) / 5,600 RPM (2RS)
ABEC ABEC-1 / ABEC-3

6208 bearing: the first 40mm-bore deep groove ball bearing in the 6200 heavy series. At 80mm OD and 18mm width, 29.1 kN dynamic load with nine 12.7mm (1/2-inch) balls. Spans IEC frame 160-180 motors from 11 kW to 15 kW. The step up from the 6207 bearing where 40mm shaft diameter becomes the industrial standard for pump impellers, compressor crankshafts, and conveyor drive pulleys.

Bore x OD x Width

40 x 80 x 18 mm

Dynamic Load Cr

29.1 kN

Static Load Cor

17.8 kN

Max Speed

8,600 RPM

Sealing

Open / ZZ / 2RS

Precision

ABEC-1 / ABEC-3


Shielding and Lubrication

The 6208 bearing ships in three configurations. Open bearings suit oil-bath, circulating-oil, or oil-mist lubrication at the full 8,600 RPM speed rating. ZZ metal shields use non-contact SPCC steel covers pressed into the outer ring, forming a labyrinth gap that blocks workshop debris, belt dust, and airborne contamination without friction penalty; speed remains 8,600 RPM.

2RS rubber seals employ nitrile (NBR) contact lips riding on the inner ring shoulder. Seal friction reduces the speed rating to 5,600 RPM. At 80mm OD, the seal contact diameter is large enough that seal friction torque becomes measurable — for motors above 3,600 RPM in sealed configuration, the seal drag alone can consume 15 to 25 watts. For IE4 and IE5 premium-efficiency motors, consider ZZ shields with an external labyrinth seal integrated into the motor end bell — this eliminates seal friction entirely while maintaining IP5X protection.

Factory fill is polyurea-thickened mineral grease at 25 to 30 percent of free internal volume. The 18mm width and 80mm OD provide approximately 14.2 cmu00b3 of grease capacity. For mining conveyor pulleys, a lithium-complex grease with MoSu2082 EP additives resists water washout. For food-processing washdown, 440C stainless steel rings and FKM seals are available. For industrial oven recirculation fans, fluorinated grease with PTFE thickener supports intermittent operation to 180u00b0C with an open configuration and machined brass cage.


Performance

The 6208 bearing delivers 29.1 kN dynamic load and 17.8 kN static load. Nine 12.7mm balls run in deep-groove raceways precision-ground to ABEC-1 or ABEC-3 tolerance. At 40mm bore, this bearing standardizes around a common industrial shaft diameter for pump impellers, compressor crankshafts, and conveyor drive pulleys. The 29.1 kN rating supports belt-tension side loads up to approximately 7.3 kN at a 1.2 service factor.

Against the 6008 bearing — same 40mm bore — the 6208 bearing adds 12mm OD (80mm vs 68mm) and 3mm width (18mm vs 15mm) for a 68 percent increase in dynamic load capacity (29.1 vs 17.3 kN). In a 15 kW belt-driven compressor at 1,450 RPM with 5.8 kN radial load, the 6208 bearing delivers approximately 26,000 hours L10 versus 8,500 hours for the 6008 bearing.

Compared to the 6207 bearing (35x72x17mm, 25.7 kN), the 6208 bearing steps up to 40mm bore with a 13 percent load gain. Ball diameter increases from 11.112mm to 12.7mm — a 14 percent gain that reduces Hertzian contact stress at the raceway. Against the 6308 bearing (40x90x23mm, 40.8 kN), the 6208 bearing saves 10mm OD and 5mm width while retaining 71 percent of the load capacity.


OEM and Customization

Yuanhe supplies the 6208 bearing with full customization. Standard internal clearance is CN. C3 clearance for electric motor drive-end and gearbox applications. C2 clearance for machine tool spindles. C4 and C5 for press-fit housings and high-thermal-gradient applications. Grease options: standard polyurea, low-noise polyurea, fluorinated high-temperature to 180u00b0C, NSF H1 food-grade. Stainless steel 440C rings and balls available; dynamic load rating decreases to approximately 23.3 kN. Cage materials: PA66, machined brass, pressed steel. Z2/V2 and Z3/V3 noise sorting available. Standard lead time is 7 to 15 days. Submit your specification or drawing for a quote.


Applications

Electric motors from 11 kW to 15 kW (IEC frame sizes 160-180), industrial fan and blower drive-end and non-drive-end bearings, centrifugal and split-case pump impeller and motor shaft bearings, air and refrigerant compressor crankshaft and motor shaft bearings, industrial gearbox input, intermediate, and output shaft bearings, medium-to-heavy conveyor head and tail pulley bearings, automotive water pump and alternator bearings in heavy-duty truck applications, machine tool spindle and feed-axis support bearings, agricultural combine harvester and baler shaft bearings, textile loom and spinning frame drive shaft bearings, material handling idler and roller bearings, HVAC air-handling unit and industrial oven recirculation fan shaft bearings, dryer drum support roller bearings, and belt-conveyor drive and snub pulley bearings. Any application requiring a 40mm shaft within an 80mm housing bore.


Frequently Asked Questions

What is the difference between the 6208 bearing and the 6008 bearing? +
Both fit a 40mm shaft. The 6208 bearing measures 80mm OD x 18mm width with 29.1 kN dynamic load. The 6008 bearing measures 68mm OD x 15mm width with 17.3 kN dynamic load — 68 percent less capacity. In a 15 kW belt-driven compressor at rated load, the 6208 bearing delivers approximately three times the L10 life of the 6008 bearing. Choose the 6008 bearing when housing diameter is the binding constraint. Choose the 6208 bearing when the bearing is expected to be a life-of-machine component.
How does the 6208 bearing compare to the 6207 bearing? +
The 6208 bearing steps up to 40mm bore (from 35mm), 80mm OD (from 72mm), and 18mm width (from 17mm). Dynamic load increases from 25.7 kN to 29.1 kN — a 13 percent gain. Ball diameter increases from 11.112mm to 12.7mm (1/2 inch) — the first half-inch ball in the 6200 series. The 14 percent increase in ball diameter reduces Hertzian contact stress, improving fatigue life beyond what the load rating increase alone would predict.
How does seal friction affect efficiency in a 6208 2RS bearing at motor speeds? +
At 80mm OD, the 6208 bearing seal contact diameter makes friction torque measurable. At 3,600 RPM, NBR contact seals consume approximately 15 to 25 watts per bearing — roughly 0.2 percent of a 15 kW motor output for a bearing pair. For premium-efficiency IE4 and IE5 motors, use ZZ shields with an external labyrinth seal integrated into the motor end bell. This eliminates seal friction entirely while maintaining IP5X-level protection.
Can the 6208 bearing be used as a locating bearing on a pump shaft? +
Yes. Axial capacity is approximately 7.3 kN (25 percent of Cr). For single-stage centrifugal pumps with 3 to 5 kN hydraulic thrust, the 6208 bearing at the drive end acts as the locating bearing. The non-drive-end bearing runs in a floating configuration (CN clearance, slip fit on outer ring) to accommodate thermal expansion. For multi-stage pumps where axial thrust exceeds 7.3 kN, pair the 6208 radial bearing with an angular contact or thrust bearing.

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