KOYO 6903-NR Bearing — Specifications, Dimensions & Cross-Reference

The KOYO 6903-NR is a deep groove ball bearing with snap ring groove manufactured by KOYO. It belongs to the 6900 series and features dimensions of 17 × 30 × 7 mm (bore × OD × width). This bearing has a dynamic load rating of 3,450 N and a static load rating of 2,070 N, making it suitable for light-duty applications.

Technical Specifications

Dimensions
Bore Diameter (d)	17 mm
Outside Diameter (D)	30 mm
Width (B)	7 mm
Weight	0.016 kg

Performance
Dynamic Load Rating (Cr)	3,450 N
Static Load Rating (C₀r)	2,070 N
Limiting Speed (Grease)	20,000 rpm
Limiting Speed (Oil)	28,000 rpm

💡 Application Note: The 6900 series bearings are commonly used in office equipment, small electric motors, and light industrial applications. The -NR suffix indicates an external snap ring groove on the outer ring, allowing easy axial location in housing bores.

Brand Cross-Reference — 6903-NR Equivalents

The following bearings from other manufacturers are interchangeable with the KOYO 6903-NR. All share identical dimensions (17×30×7mm) and comparable load ratings:

Brand	Part Number	Dynamic Load (N)	Static Load (N)
KOYO	KOYO 6903-NR ✦	3,450	2,070
NTN	NTN 6903-NR	3,450	2,070
NACHI	NACHI 6903-NR	3,450	2,070
FAG	FAG 6903-NR	3,450	2,070
Timken	Timken 6903-NR	3,450	2,070
NSK	NSK 6903-NR	3,450	2,070
NTN	NTN 6903-NR	3,450	2,070
SKF	SKF 6903-NR	3,450	2,070

Available Variants

The KOYO 6903 base bearing is available in these configurations:

KOYO 6903-ZZ-C3

"Double shielded

KOYO 6903-ZZ

Double metal shielded

KOYO 6903-C3

"Open

KOYO 6903-2Z

Double metal shielded (ISO)

KOYO 6903-2RS-C3

"Double sealed

KOYO 6903-2RS

Double rubber sealed

KOYO 6903

Open (no seal/shield)

Frequently Asked Questions

What are the dimensions of the KOYO 6903-NR?

The KOYO 6903-NR has a bore diameter of 17mm, outside diameter of 30mm, and width of 7mm. It weighs 0.016kg.

What is the load capacity of the KOYO 6903-NR?

The dynamic load rating (Cr) is 3,450 N and the static load rating (C₀r) is 2,070 N. The maximum recommended speed is 20,000 rpm with grease lubrication or 28,000 rpm with oil lubrication.

What bearings are equivalent to KOYO 6903-NR?

The 6903-NR is manufactured by multiple brands including SKF, NTN, NSK, FAG, Timken, KOYO, and NACHI. All versions share the same 17×30×7mm dimensions and are interchangeable in most applications. See the cross-reference table above for detailed comparisons.