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688 — 8 × 16 × 4 mm

BOUNDARY DIMENSIONSUNIT / mm
B = 4 mmD = 16 mmd = 8 mm
Boundary dimensions · schematic, not a product photograph or manufacturing drawing.
Deep groove ball

688

688 is a deep groove ball designation documented on BearingIndex from 5 independent manufacturer publications. The published boundary dimensions are 8 × 16 × 4 mm. The publishing works are in Zhejiang, Fujian, Shanghai provinces, China. Every value below comes from that manufacturer’s own published material, with the date it was recorded.

Bore d
8 mm
Outside D
16 mm
Width B
4 mm

Compare the 5 publications

Manufacturers publish different values for this designation.

B: 4 / 5 mm. Confirm the dimension against the specific manufacturer drawing before specifying.

What each manufacturer published.

ManufacturerWidth (mm)Dynamic load rating (kN)Static load rating (kN)Limiting speed — grease (rpm)Limiting speed — oil (rpm)Reference mass (kg)Source recorded
Sihai
688
4—————2026-09-24Request
SFH
688
4—————2026-09-24Request
Runstar
688
4—————2026-09-24Request
Yuyao Global
688
5—————2026-09-24Request
RCL
688
51.60.7136000430000.00382026-09-24Request

A dash means that manufacturer did not publish the value. Dimensions every source agrees on are shown above rather than repeated per row.

Where the sources agree.

PropertyFindingSources
WidthRanges 4 – 5 mm across 5 sources5

Where the figures differ, use the drawing from the manufacturer you buy from.

Calculated from the published values.

FigureHow it is obtainedResult
Radial section height(D − d) / 24 mm
Mean diameter dm(D + d) / 212 mm
Speed factor dm · nmean diameter × highest published limiting speed516,000 mm·min−1
C / C₀ load ratiodynamic ÷ static load ratingRCL 2.25

Arithmetic on the figures above — not a bearing life calculation for your load case.

The works that publish 688.

RCL

Ningbo, Zhejiang, China

Thin-wall ball bearings for compact mechanisms

Ningbo Shilong manufactures high-precision bearings under the RCL name. Its published catalogue includes 67, 68, 69 and 60 series, with an emphasis on thin-wall bearings for compact mechanisms. Application pages identify encoders, motors, robots, bicycles and circular looms. Space envelope and rotational requirements are useful starting points for a technical inquiry.

Published ranges: 67- and 68-series thin-wall bearings · 69-series ball bearings · 60-series ball bearings

131 designations documented here · 1 reviewed evidence record · source recorded 2026-09-24

Ask RCL about 688

Runstar

Zhangzhou, Fujian, China

Miniature ball and thrust bearings

Zhangzhou Runshida manufactures miniature and small deep groove ball bearings and flat thrust ball bearings under the Runstar name. Its published company scope gives a bore range of 1–50 mm and includes nonstandard development. Applications span instruments, small motors, appliances, medical equipment and fishing tackle; dimensions and closures still require model-specific confirmation.

Published ranges: Miniature deep groove ball bearings · Small deep groove ball bearings · Flat thrust ball bearings · Nonstandard miniature designs

223 designations documented here · 1 reviewed evidence record · source recorded 2026-09-24

Ask Runstar about 688

SFH

Shanghai, China

Miniature and thin-section ball bearings

Shanghai Hengan manufactures miniature bearings under the SFH brand, with a factory in Wuxi and technical and inspection functions in Shanghai. Its catalogue covers metric, inch and flanged deep groove bearings, thin-section designs, double-row angular contact bearings and thrust bearings. Special nonstandard designs are also listed.

Published ranges: Metric and inch miniature deep groove bearings · Flanged miniature bearings · Thin-section ball bearings · Double-row angular contact and thrust bearings

51 designations documented here · 1 reviewed evidence record · source recorded 2026-09-24

Ask SFH about 688

Sihai

Ningbo, Zhejiang, China

Deep groove bearings for motors and automotive use

Cixi Sihai develops and manufactures deep groove ball bearings. Its published scope gives a bore range of 6–35 mm and lists 6000, 6200, 6300, 6800 and 6900 series. Applications include vehicles, appliances, power tools, instruments and office equipment. Automotive engine-related references should be matched to the exact assembly.

Published ranges: 6000, 6200 and 6300 series · 6800 and 6900 series · Automotive engine-bearing applications

85 designations documented here · 1 reviewed evidence record · source recorded 2026-09-24

Ask Sihai about 688

Yuyao Global

Ningbo, Zhejiang, China

Miniature and small bearings

Yuyao Global manufactures miniature and small bearings. Its published product organization includes rubber-sealed and metal-shielded designs, with applications in appliances, automotive systems, communications equipment and medical devices. The company describes manufacturing and inspection operations in Yuyao; closure type and lubrication should be agreed for the operating environment.

Published ranges: Miniature and small bearings · Rubber-sealed bearing designs · Metal-shielded bearing designs

71 designations documented here · 1 reviewed evidence record · source recorded 2026-09-24

Ask Yuyao Global about 688

Applications the publishing works state.

ApplicationStated by
Automotive systemsSihai, Yuyao Global
BicyclesRCL
Circular loomsRCL
Communications equipmentYuyao Global
Encoders and motorsRCL
Fishing tackleRunstar
Household appliancesSihai, Yuyao Global
Medical equipmentRunstar, Yuyao Global
Office equipmentSihai
Power toolsSihai
Precision instrumentsRunstar
Precision machinerySFH
Precision motorsSFH
RoboticsRCL
Small motorsRunstar

Application areas each manufacturer states for its own range. Confirm load, speed, temperature and lubrication for your case.

Not documented by any source here.

Precision class · Internal clearance · Sealing · Material · Cage material · Z class · V class · Limiting speed · Lubrication · Operating temperature · Precision standard · Ring material · Rolling element material · Noise / vibration test method · Manufacturer series · Manufacturer suffix · Ball count · Ball diameter.

Ask the manufacturer for these when you enquire.

Other designations with the same 8x16x4 mm envelope.

DesignationBearing familyWorks
688ZZ/2RSDeep groove ball1
S688ZZ/2RSDeep groove ball1

Same envelope, but sealing, internal design, clearance and load capability differ — not interchangeable by default.

Neighbouring designations documented here.

DesignationEnvelope d × D × B (mm)Bearing familyWorks
680010 × 19 × 5Ball bearings5
6800W710 × 19 × 7Deep groove ball1
6800ZZ/2RS10 × 19 × 5Deep groove ball1
680112 × 21 × 5Deep groove ball4
6801ZZ/2RS12 × 21 × 5Deep groove ball1
680215 × 24 × 5Deep groove ball4
6802ZZ/2RS15 × 24 × 5Deep groove ball1
680317 × 26 × 5Deep groove ball4
6803zz17 × 26 × 5Deep groove ball1
6803ZZ/2RS17 × 26 × 5Deep groove ball1
680420 × 32 × 7Deep groove ball5
6804ZZ/2RS20 × 32 × 7Deep groove ball1
680525 × 37 × 7Deep groove ball5
6805ZZ/2RS25 × 37 × 7Deep groove ball1
680630 × 42 × 7Deep groove ball5
6806ZZ/2RS30 × 42 × 7Deep groove ball1
680735 × 47 × 7Deep groove ball3
6807ZZ/2RS35 × 47 × 7Deep groove ball1

Each envelope shown is that designation’s own published size.

Request a quote for 688.

Tick the works you want above, then send one enquiry — each manufacturer answers you separately and cannot see the others.

Open your enquiry How sourcing works here →

Figures on this page are each manufacturer’s own published material, recorded on the dates shown. How we check sources →