THE BEARINGINDEX DIRECTORY

51103 — 17 × 30 × 9 mm

BOUNDARY DIMENSIONSUNIT / mm

Boundary dimensions · schematic, not a product photograph or manufacturing drawing.

Thrust

51103

51103 is a thrust designation documented on BearingIndex from 2 independent manufacturer publications. The published boundary dimensions are 17 × 30 × 9 mm. The designation ends in bore code 03, which resolves to a 17 mm bore under ISO 15 and matches what the manufacturers published. The publishing works are in Zhejiang, Fujian provinces, China. Every value below comes from that manufacturer’s own published material, with the date it was recorded.

Bore d: 17 mm
Outside D: 30 mm
Width B: 9 mm

Compare the 2 publications

What each manufacturer published.

Manufacturer	Reference mass (kg)	Source recorded
Runstar 51103	0.024	2026-09-24	Request
PLB 51103	0.025	2026-09-24	Request

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.

Property	Finding	Sources
Reference mass	Ranges 0.024 – 0.025 kg across 2 sources	2

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

Calculated from the published values.

Figure	How it is obtained	Result
Radial section height	(D − d) / 2	6.5 mm
Mean diameter d_m	(D + d) / 2	23.5 mm

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

The works that publish 51103.

PLB

Ningbo, Zhejiang, China

Motor, steering and custom precision bearings

Cixi Lingfan manufactures bearings under the PLB name. Its company presentation describes automotive alternator and steering bearings, motor bearings, precision spindle bearings and nonstandard designs. The published production envelope is bore 3–40 mm and outside diameter 10–100 mm, subject to exact model confirmation. Buyers should include the intended assembly and operating conditions.

Published ranges: Automotive alternator and steering bearings · Motor bearings · Precision spindle-bearing applications · Nonstandard bearing designs

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

Ask PLB about 51103

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 51103

Applications the publishing works state.

Application	Stated by
Automotive systems	PLB
Electric motors	PLB
Fishing tackle	Runstar
Machine-tool spindles	PLB
Medical equipment	Runstar
Precision instruments	Runstar
Small motors	Runstar

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 · Dynamic load rating · Static load rating · Limiting speed · Lubrication · Operating temperature · Precision standard · Ring material · Rolling element material · Limiting speed — grease · Limiting speed — oil · Noise / vibration test method · Manufacturer series · Manufacturer suffix · Ball count · Ball diameter.

Ask the manufacturer for these when you enquire.

Neighbouring designations documented here.

Designation	Envelope d × D × B (mm)	Bearing family	Works
51100	10 × 24 × 9	Thrust	2
51101	12 × 26 × 9	Thrust	2
51102	15 × 28 × 9	Thrust	2
51104	20 × 35 × 10	Thrust	2
51105	25 × 42 × 11	Thrust	2
51106	30 × 47 × 11	Thrust	1
51107	35 × 52 × 12	Thrust	1
51108	40 × 60 × 13	Thrust	1
51109	45 × 65 × 14	Thrust	1
51110	50 × 70 × 14	Thrust	1
51111	55 × 78 × 16	Thrust	1
51112	60 × 85 × 17	Thrust	1
51113	65 × 90 × 18	Thrust	1
51114	70 × 95 × 18	Thrust	1
51115	75 × 100 × 19	Thrust	1
51116	80 × 105 × 19	Thrust	1
51117	85 × 110 × 19	Thrust	1
51118	90 × 120 × 22	Thrust	1

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

Request a quote for 51103.

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 →

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