Home > 6805 Thin-Section Deep Groove Ball Bearing 25x37x7mm

6805 Thin-Section Deep Groove Ball Bearing 25x37x7mm

When a 25mm shaft needs bearing support but radial space is tight, the 6805 bearing fits where a 6005 bearing cannot. At 37mm OD and 7mm width, it saves 10mm of housing diameter and 5mm of axial stack versus the 6005 bearing while still handling 4.30 kN dynamic load.

Key Specifications

Sealing: Open, ZZ non-contact metal shields, or 2RS double nitrile rubber contact seals. Three configurations for oil-bath, grease-packed, and contamination-resistant installations.
Speed and Load: 22,000 RPM (open), 19,000 RPM (ZZ), 15,000 RPM (2RS). 4.30 kN dynamic load (Cr), 2.88 kN static load (Cor) at CN clearance.
Material and Precision: GCr15 bearing steel (AISI 52100 equivalent), through-hardened to HRC 60-64. Standard ABEC-3. ABEC-5 available on request.
Operating Direction: Deep groove raceway for bidirectional radial loads. Axial capacity approximately 10% of Cr due to the 7mm thin cross-section limiting contact angle shift.
Temperature Range: -20C to 120C with NBR seals and standard polyurea-mineral grease. High-temperature grease variants extend to 150C continuous.

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6805 Bearing Technical Specifications

Model	6805
Bearing Type	Deep Groove Ball Bearing, Thin Section, Single Row
Sealing	Open / ZZ (Metal Shield) / 2RS (Rubber Seal)
Bore Dia. (d)	25 mm
Outside Dia. (D)	37 mm
Width (B)	7 mm
Precision	ABEC-3 (Standard), ABEC-5 Available
Dynamic Load (Cr)	4.30 kN
Static Load (Cor)	2.88 kN
Max Speed	22,000 RPM (Open) / 19,000 (ZZ) / 15,000 (2RS)
Temp. Range	-20°C to 120°C (NBR) / Up to 150°C (HT Grease)
Ring & Ball Material	GCr15 (AISI 52100), HRC 60-64
Seal Material (2RS)	Nitrile Rubber (NBR) + Steel Insert
Lubrication	Polyurea-Mineral Grease, NLGI 2

Bore x OD x Width

25 x 37 x 7 mm

Dynamic Load Cr

4.30 kN

Static Load Cor

2.88 kN

Max Speed

22,000 RPM

Sealing

Open / ZZ / 2RS

Precision

ABEC-3

Shielding and Lubrication

The 6805 bearing ships in three sealing configurations, each matched to a distinct operating environment. Open bearings reach 22,000 RPM without seal drag and are specified for oil-bath or oil-mist systems where the housing provides contamination control. The thin 7 mm cross-section reduces centrifugal force on the rolling elements, enabling higher speed limits than the 12 mm-wide 6005 bearing (22,000 vs 15,000 RPM open).

ZZ metal-shielded 6805 bearings use non-contact steel shields with a 0.2 mm to 0.4 mm gap between the shield and inner ring land. They run to 19,000 RPM and suit robotic joint actuators, dental handpiece spindles, and precision instrument drives where low torque and minimal heat generation are requirements. The non-contact design adds negligible drag: torque increase over an open 6805 bearing is under 2% at 10,000 RPM.

2RS rubber-sealed 6805 bearings use nitrile contact seals on the inner ring land. At 15,000 RPM, the 2RS 6805 bearing handles encoder spindles, small servo motors, and medical pump drives where the bearing must exclude fine particulate without external shielding. The 7 mm width limits the grease reservoir: expect shorter relubrication intervals than wider bearings. A 6805-2RS bearing filled with standard polyurea-mineral grease (NLGI 2) operates sealed-for-life at 10,000 RPM and 60 degrees C for 1,500 to 3,000 hours under moderate radial load (less than or equal to 0.8 kN).

Performance

The 6805 bearing delivers 4.30 kN dynamic load capacity (Cr) and 2.88 kN static load capacity (Cor). This is lower than the 6005 bearing (10.1 kN Cr, 5.85 kN Cor) on the same 25 mm shaft, but the trade-off is a 10 mm OD reduction (37 mm vs 47 mm) and a 5 mm width reduction (7 mm vs 12 mm). The 6805 bearing is not a downgrade from the 6005 bearing: it serves a different design constraint. When the housing wall thickness limits the bearing OD to under 40 mm, the 6805 bearing is the highest-capacity single-row deep groove ball bearing available at 25 mm bore.

Within the 6800 thin-section series, the 6805 bearing sits at the midpoint. The 6804 bearing (20x32x7 mm) offers 3.15 kN Cr on a 20 mm shaft. The 6806 bearing (30x42x7 mm) steps up to 4.70 kN Cr on a 30 mm shaft. At 25 mm bore, the 6805 bearing is the only option in the series: the 6905 bearing (25x42x9 mm) adds 5 mm OD for 7.0 kN Cr, but forfeits the thin-section advantage. For designers constrained to a 37 mm maximum bearing OD on a 25 mm shaft, the 6805 bearing is the specification.

Radial internal clearance is CN as standard. C2 clearance is common for the 6805 bearing in precision spindle applications where minimal radial play is required. The thin 7 mm cross-section means running clearance changes more with housing material than in wider bearings: in an aluminum housing at 80 degrees C, thermal expansion of the housing bore adds approximately 8 to 12 microns of clearance compared to a steel housing. Specify C2 clearance in aluminum housings to maintain preload at operating temperature.

OEM and Customization

Yuanhe supplies the 6805 bearing with full customization for volume OEM orders. Non-standard radial clearances (C2, CN, C3) are stocked or produced to order. Lubrication options include low-torque synthetic grease for instrument bearings, food-grade grease (NSF H1 registered) for processing equipment, and high-temperature polyurea grease rated to 150 degrees C continuous. Stainless steel 440C rings and balls are available for corrosive or washdown environments: note that 440C derates dynamic load capacity by approximately 15% compared to GCr15. Cage options include stamped steel (standard, to 22,000 RPM), glass-reinforced polyamide (reduced weight, lower noise, to 15,000 RPM), or machined brass (high-speed stability above 19,000 RPM). Standard MOQ is 100 pieces per configuration. Sample orders of 10 to 50 pieces ship within 7 days. Every order includes a dimensional inspection report covering bore, OD, width, radial runout, and radial clearance. ISO 9001:2015 certified. Submit your drawing or specification for a same-day quote.

Applications

Robotic joint actuators and harmonic drive input bearings, dental handpiece turbine spindles, medical pump and centrifuge drives, precision encoder and resolver spindles, small servo motor rotor supports, optical inspection equipment rotary stages, 3D printer extruder drive shafts, laboratory centrifuge rotors, textile spindle bearings, high-speed spindle motors under 500 W. Any 25 mm shaft application requiring a bearing OD under 40 mm with speeds above 15,000 RPM.

Frequently Asked Questions

How much radial space does a 6805 bearing save compared to a 6005 bearing on the same 25 mm shaft? +

The 6805 bearing saves 10 mm of housing diameter (37 mm OD vs 47 mm OD) and 5 mm of axial width (7 mm vs 12 mm) compared to a 6005 bearing on the same 25 mm shaft. Housing wall thickness at the bearing seat reduces by 5 mm radially. Volume comparison: the 6805 bearing occupies approximately 41% less envelope volume than the 6005 bearing. The trade-off is lower load capacity: 4.30 kN Cr vs 10.1 kN Cr. Use the 6805 bearing when housing diameter is the primary constraint. Use the 6005 bearing when load capacity governs the design.

At what speed does the thin 7 mm cross-section of the 6805 bearing become an advantage over wider alternatives? +

The thin cross-section advantage becomes measurable above 12,000 RPM. At 22,000 RPM, the 6805 open bearing runs approximately 8 degrees C to 12 degrees C cooler than a 6005 open bearing at the same speed, because the smaller rolling elements generate less centrifugal force and the thinner rings dissipate heat faster to the housing. The 7 mm width also reduces grease churning losses in ZZ and 2RS configurations: at 15,000 RPM, the 6805-2RS bearing draws approximately 30% less no-load torque than a 6005-2RS bearing. For high-speed spindles above 18,000 RPM, the 6805 bearing is the recommended deep groove option in the 25 mm bore class.

What mounting tolerance is required for a 6805 bearing in a precision spindle application? +

For precision spindle applications (runout under 5 microns), the 6805 bearing requires: shaft diameter tolerance h5 or tighter (25 mm+0/-0.009 mm), housing bore tolerance H6 (37 mm+0.016/0 mm), shaft shoulder squareness under 3 microns per 25 mm of diameter, and housing bore shoulder squareness under 5 microns. The thin 7 mm cross-section of the 6805 bearing is less forgiving of misalignment than wider bearings: a 0.01 mm housing bore ovality causes approximately 40% more localized raceway stress than the same error in a 12 mm-wide 6005 bearing. Use a calibrated expanding mandrel for mounting. Press-fitting directly onto the shaft is not recommended for ABEC-5 6805 bearings; heat the bearing to 80 degrees C to 100 degrees C for slip-fit installation.

How does the 7 mm width of the 6805 bearing affect its axial load capacity compared to wider bearings? +

The 7 mm width reduces axial load capacity to approximately 10% of Cr (about 0.43 kN sustained) compared to 20% for a standard-width deep groove ball bearing. The shallow raceway groove depth in the 6805 bearing limits the contact angle shift under axial load: at 0.43 kN axial, the contact angle reaches approximately 10 degrees before the ball approaches the raceway shoulder edge. For applications requiring combined radial-axial loading above 2.5 kN radial with more than 0.5 kN axial, the 6905 bearing (25x42x9 mm) provides a wider cross-section with 7.0 kN Cr and approximately 20% axial capacity. For pure axial loads on a 25 mm shaft, specify a thrust ball bearing instead.