Cross-brand designation analysis
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Same-model Comparison
Explore products that share a base designation across loaded brands, with dimensional agreement and data gaps shown clearly.
Automatic candidate selection
One base designation across loaded brands
Exact designations rank first. Dimensions, suffixes and other technical differences remain visible so the result is not mistaken for an interchangeability declaration.
Designation candidates
“6903” across 4 loaded brands
One highest-ranked designation candidate is shown per manufacturer. Use Custom Compare when you want to choose exact suffix variants yourself.
Technical comparison
Choose exact variants instead →Brand differences at a glance
| Parameter | NSK690317 × 30 × 7 mm | KOYO690317 × 30 × 7 mm | NACHI690317 × 30 × 7 mm | EZO690317 × 30 × 7 mm |
|---|---|---|---|---|
| Comparable specifications | ||||
| Brand | NSK | KOYO | NACHI | EZO |
| Designation | 6903 | 6903 | 6903 | 6903 |
| Product family | Single row deep groove ball bearings | Single-row / Open type | Deep groove ball bearing | Thin-Section Ball Bearing |
| Detailed type | Deep groove ball bearings | Deep groove ball bearings | Deep groove ball bearings | Deep groove ball bearings |
| Bore diameterd | 17 mm | 17 mm | 17 mm | 17 mm |
| Outside diameterD | 30 mm | 30 mm | 30 mm | 30 mm |
| WidthB | 7 mm | 7 mm | 7 mm | 7 mm |
| Basic dynamic load ratingC | 5.05 kN | 5.75 kN | 5.8 kN | 4.59 kN |
| Basic static load ratingC0 | 2.55 kN | 2.55 kN | 2.55 kN | 2.56 kN |
| Fatigue load limitPu | — | 0.13 kN | — | — |
| Limiting speednG | — | 23000 r/min | — | — |
| Mass≈m | 0.017 kg | 0.018 kg | 0.018 kg | 0.0156 kg |
| Sealing | Open | Open | Open | Open (no closure suffix in this catalogue marking) |
| Bearing material | — | — | — | High-carbon chromium bearing steel |
| Boundary dimensions | ||||
| Bearing widthB | 7 mm | — | 7 mm | — |
| Outer diameterD | — | — | — | 30 mm |
| Minimum bearing chamferr min. | 0.3 mm | — | 0.3 mm | — |
| Outer diameterD | — | — | — | 1.1811 inch |
| Inner ring widthB | — | — | — | 7 mm |
| Inner ring widthB | — | — | — | 0.2756 inch |
| Outer ring widthC | — | — | — | 7 mm |
| Outer ring widthC | — | — | — | 0.2756 inch |
| Inner ring chamfer dimensionr si min | — | — | — | 0.3 mm |
| Inner ring chamfer dimensionr si min | — | — | — | 0.0118 inch |
| Outer ring chamfer dimensionr se min | — | — | — | 0.3 mm |
| Outer ring chamfer dimensionr se min | — | — | — | 0.0118 inch |
| Classification | ||||
| Official Category Path | — | Deep groove ball bearings - Single-row - Open type | — | — |
| Official Classification 1 | — | Deep groove ball bearings / Single-row / Open type | — | — |
| Construction | ||||
| Closure arrangement | — | — | Open | — |
| Listed closure suffix | — | — | None (open type) | — |
| Catalogue closure construction | Open | — | — | — |
| Closure interpretation | — | — | — | Open (no closure suffix in this catalogue marking) |
| Material interpretation | — | — | — | High-carbon chromium bearing steel |
| Equivalent-load factors | ||||
| Catalogue load calculation factorf0 | — | — | 14.7 | — |
| Load ratings | ||||
| Basic dynamic radial load ratingCr | 5050 N | — | 5800 N | — |
| Basic static radial load ratingC0r | 2550 N | — | 2550 N | — |
| Equivalent-load calculation factorf0 | 14.7 | — | — | — |
| Lubrication-qualified speed | ||||
| Limiting speed with grease | 24000 r/min | — | — | — |
| Limiting speed with oil (open bearing) | 28000 r/min | — | — | — |
| Limiting speed with grease (open) | — | — | 24000 r/min | — |
| Limiting speed with oil (open) | — | — | 29000 r/min | — |
| Catalogue limiting speed (grease) | — | — | — | 22000 r/min |
| Catalogue limiting speed (oil) | — | — | — | 26000 r/min |
| Manufacturer Identity | ||||
| Official Class Key | — | 010-010-010 | — | — |
| Mounting dimensions | ||||
| Minimum shaft shoulder diameterda min. | 19 mm | — | 19 mm | — |
| Maximum shaft shoulder diameterda max. | 19.5 mm | — | — | — |
| Maximum housing shoulder diameterDa max. | 28 mm | — | 28 mm | — |
| Maximum adjacent fillet radiusra max. | — | — | 0.3 mm | — |
| Maximum shaft or housing fillet radiusra max. | 0.3 mm | — | — | — |
| Adjacent mounting dimension (da min)da min | — | — | — | 28 mm |
| Adjacent mounting dimension (da min)da min | — | — | — | 1.1024 inch |
| Adjacent mounting dimension (da max)da max | — | — | — | 28.5 mm |
| Adjacent mounting dimension (da max)da max | — | — | — | 1.122 inch |
| Adjacent mounting dimension (r asi max)r asi max | — | — | — | 0.3 mm |
| Adjacent mounting dimension (r asi max)r asi max | — | — | — | 0.0118 inch |
| Adjacent mounting dimension (r ase max)r ase max | — | — | — | 0.3 mm |
| Adjacent mounting dimension (r ase max)r ase max | — | — | — | 0.0118 inch |
| Reference mass | ||||
| Catalogue row mass (variants not individually specified) | — | — | 0.018 kg | — |
| Approximate catalogue mass (open reference) | 0.017 kg | — | — | — |
| Reference mass | — | — | — | 15.6 g |
| Rolling elements | ||||
| Ball diameterDw | — | — | — | 3.969 mm |
| Ball quantityZ | — | — | — | 11 |
| Technical Data | ||||
| d | — | 30 mm | — | — |
| B | — | 7 mm | — | — |
| R(Min.) | — | 0.3 mm | — | — |
| Basic Load Ratings : Cr | — | 5.75 kN | — | — |
| Basic Load Ratings : C0R | — | 2.55 kN | — | — |
| Fatigue Load Limit : Cu | — | 0.130 kN | — | — |
| Factor : F0 | — | 14.7 | — | — |
| Limiting Speeds(Grease Lub.) | — | 23000 min-1 | — | — |
| Limiting Speeds(Oil Lub.) | — | 28000 min-1 | — | — |
| Da(Min.) | — | 19 mm | — | — |
| Da(Max.) | — | 28 mm | — | — |
| Ra(Max.) | — | 0.3 mm | — | — |
| Mass(Refer.) | — | 0.018 kg | — | — |
Automatic matching is a search aid, not an interchangeability declaration. Confirm the full suffix, tolerances, internal design and application limits before substitution.