SB204 Bearing Dimensions
SB204 light-series insert bearing: 20 mm bore, 47 mm spherical OD, 25 mm inner ring width, set-screw lock. Designation and size-equivalent codes. Quote.
SB204 specifications
| Bore d | 20 mm |
|---|---|
| Outside diameter D | 47 mm |
| Inner ring width B | 25 mm |
| Outer ring width C | 14 mm |
| Seal / shield options | Sealed insert bearing (SB type), spherical outside diameter, set-screw locking |
| Material | GCr15 chrome bearing steel (rings and rolling elements) |
| Precision | P0 (standard) |
| Radial clearance | C0 (standard); C3 on request |
| Load ratings | Load ratings for this model are being checked against FULI's catalog. Ask for them with the quote. |
Dimensions cross-checked against published catalogues; please confirm with your quote.
How to read the SB204 designation
| Segment | Meaning |
|---|---|
| SB | Insert bearing with set-screw locking and spherical outside diameter; inner ring narrower than the UC type |
| 2 | 200 series |
| 04 | Bore code 04 → 20 mm bore. ISO bore code (00–03 = 10/12/15/17 mm; 04 and above = code × 5 mm). |
SB204 interchange
SB204 is a set-screw insert bearing. SB inserts are made to common catalogue sizes, with a narrower inner ring than the UC type of the same bore. Check the dimensions above against your shaft and housing, or send us the old part number and we confirm the match.
Brand names are trademarks of their respective owners. FULI is not affiliated with, authorized by or endorsed by these companies. Part numbers are shown for interchange reference only. FULI dimensions, load ratings and speeds come from the FULI catalog.
SB204 compared with nearby sizes and housings
SB204 is a narrow set-screw insert for a 20 mm shaft: outside diameter 47 mm, inner ring width 25 mm and outer ring width 14 mm.
The housed units of the same size code, UCP204 (pillow block unit), UCF204 (square flange unit) and UCFL204 (oval flange unit), are built around the UC204 insert, not SB204. Other inserts with the same size code are UC204 (20 × 47 × 31 mm) and SA204 (20 × 47 × 21.5 mm).
SB205 is the next larger size in the same series on this site: shaft d 25 mm (5 mm more), outside diameter D 52 mm (5 mm more) and inner ring width B 27 mm (2 mm more).
SB203 is the next smaller size in the same series on this site: shaft d 17 mm (3 mm less), outside diameter D 40 mm (7 mm less) and inner ring width B 22 mm (3 mm less).
| Model | Type | Main dimensions | Weight (kg) |
|---|---|---|---|
| SB204 | insert bearing (this page) | 20 × 47 × 25 mm (d × D × B) | — |
| SB203 | insert bearing | 17 × 40 × 22 mm (d × D × B) | — |
| SB205 | insert bearing | 25 × 52 × 27 mm (d × D × B) | — |
| UC204 | insert bearing | 20 × 47 × 31 mm (d × D × B) | 0.17 |
| SA204 | insert bearing | 20 × 47 × 21.5 mm (d × D × B) | — |
| UCP204 | pillow block unit | d 20 · H 33.3 · J 95 mm (JIS) | 0.7 |
| UCF204 | square flange unit | d 20 · L 86 · J 64 mm | — |
| UCFL204 | oval flange unit | d 20 · L 113 · J 90 mm | — |
Dimensions in mm from the model pages; weight from FULI's catalog, — = not listed on this site.
SB204 load ratings
FULI's catalog has no load rating line for SB204 itself, so none is given here. Ask us and we send the figures with the quotation.
SB204 dimensions in inches
The nearest common inch shaft size to the 20 mm bore of SB204 is 13/16 in (20.64 mm), 0.64 mm larger than the bore, so SB204 will not go on it. An inch shaft needs an inch bore insert. Inch bore versions are made for some sizes; ask us with the shaft size.
| Dimension | Millimetres | Inches |
|---|---|---|
| Bore d | 20 mm | 0.7874 in |
| Outside diameter D | 47 mm | 1.8504 in |
| Inner ring width B | 25 mm | 0.9843 in |
| Outer ring width C | 14 mm | 0.5512 in |
Converted at 1 in = 25.4 mm and rounded to four decimals. The bearing itself is made to the millimetre sizes.
Mounting SB204 (general guidance)
General guidance, not a FULI specification: insert bearings slide onto the shaft rather than being pressed on, and are held by their locking device. A shaft ground or drawn to h7 is common; a closer shaft such as js7 or j7 suits higher speed.
SB204 is locked by set screws in the extended inner ring. Housed-unit problems usually start at the set screws: if the inner ring is not held, it turns on the shaft and wears it. Tighten each screw to the torque in the mounting instructions, and check them again after the first hours of running.
The spherical outside diameter of SB204 lets the insert swivel in the housing seat while it is being mounted, which takes up small errors in shaft line. It does not make the bearing a self-aligning bearing in service.
Grease for SB204
The insert is sealed on both sides and greased at the factory. Fitted in a housing with a grease fitting, it can be relubricated through the housing; on its own it runs on the factory fill.
Greases for a stated temperature range can be specified on the order; for North America a range of −40 to 120 °C is often asked for.
How FULI supplies SB204
FULI supplies SB204 on its own as a replacement insert, or fitted in a housing as a complete unit. The rings and balls are GCr15 chrome steel and the radial clearance is C0 as standard, with C3 on request.
Rings are marked with a brand you are authorised to use, with the FULI brand, or left neutral, as your order states. The box is printed with the model, precision class and brand.
Inquiries that leave out the prefix or suffix letters are the usual cause of a wrong quote, so write the full designation, for example SB204.
Tools and guides for SB204
Typical applications
- Replacement inserts for UCP / UCF / UCFL housings
- Conveyors
- Agricultural machinery
FAQ
What shaft size does SB204 fit?
A 20 mm shaft (0.7874 in).
What is the difference between SB204 and SB205?
SB205 is the next size up, for a 25 mm shaft, with outside diameter D 52 mm (5 mm more) and inner ring width B 27 mm (2 mm more). Choose SB205 when the shaft is larger or the load is higher; the housings are not interchangeable.
What is the difference between SB204 and UC204?
Both fit a 20 mm shaft with a 47 mm outside diameter. SB204 has an inner ring 25 mm wide and UC204 31 mm. Both lock with set screws. Check that the narrower or wider ring clears the housing and the parts beside it on the shaft.
Can SB204 be ordered on its own?
Yes. SB204 is quoted as an insert bearing on its own. Tell us the housing or machine it goes into and we check the fit before quoting.
Where are the load ratings for SB204?
Load ratings for SB204 are being checked against FULI's catalog and are not shown on this page yet. Model pages with a "Load ratings & speed" table carry values from FULI's catalog.