30304 Bearing Dimensions
30304 is a tapered roller bearing with a 20 mm bore, 52 mm outer diameter and 16.25 mm total width (20×52×16.25 mm, ISO 355). Cone and cup widths, designation breakdown and size-equivalent codes.
30304 specifications
| Bore d | 20 mm |
|---|---|
| Outside diameter D | 52 mm |
| Total width T | 16.25 mm — assembled width of cup and cone |
| Seal / shield options | Open (cup and cone, no seals) |
| Material | GCr15 chrome bearing steel (rings and rolling elements) |
| Precision | P0 (standard); P6 on request |
| Radial clearance | Set during mounting (adjustable, not a C-class value) |
Load ratings & speed
| Dynamic load rating Cr | 33.10 kN |
|---|---|
| Static load rating C0r | 33.20 kN |
| Weight | 0.166 kg — approx. |
Values from FULI's catalog; confirm for your application.
Nearby 30200/30300 series sizes: 30211 bearing · 30212 bearing · 30305 bearing · 30306 bearing
Grease quantity for 30304: bearing grease fill calculator.
Buying 30304 in quantity? See bearing wholesale supplier for pricing by quantity and shipping, and bearing manufacturer in China for how to check the factory.
How to read the 30304 designation
| Segment | Meaning |
|---|---|
| 3 | Single row tapered roller bearing (metric, ISO 355) |
| 03 | Dimension series 03 |
| 04 | Bore code 04 → 20 mm bore. ISO bore code (00–03 = 10/12/15/17 mm; 04 and above = code × 5 mm). |
30304 cross reference by brand
30304 is an ISO designation: bore d, outside diameter D and total width T are the same at each maker. The letters each maker adds are series, design or cage codes, not seal codes, so the full number is different at every brand. The table below lists the checked form for each one.
FULI catalog: 20 × 52 × 16.25 mm (d × D × T).
| Brand | Designation |
|---|---|
| FULI | 30304 |
| SKF | 30304 |
| Timken | 30304 |
| NSK | HR30304J |
| NTN | 4T-30304A |
| Koyo | 30304AJR |
| FAG | 30304-A |
- SKF's catalog table lists the basic number 30304. We have found its full order number in one source only, so it is not shown here; send us your SKF number and we will check it.
- Cone width B (inner ring) is not the same at every maker: 15 mm at NSK and Timken, 16 mm at NTN and Koyo. Bore d, outside diameter D, total width T and cup width C (13 mm) match. If your fit depends on B, tell us which brand you are replacing.
- Timken page: full tapered roller table (SKF, NSK, NTN, Koyo, FAG columns)
- SKF page: J2/Q and B suffixes
- NSK, NTN, Koyo and NACHI page: HR…J, 4T- and JR
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.
Tolerances and fits for 30304
FULI makes 30304 to P0 as standard, with P6 on request. P0 is the Normal tolerance class of ISO 492; P6 limits are tighter. These are the P0 limits for the 20 × 52 × 16.25 mm size.
| Dimension | Nominal, mm | Deviation, µm | Limits, mm |
|---|---|---|---|
| Bore d (Δdmp) | 20 | 0 / −12 | 20.000 / 19.988 |
| Outside diameter D (ΔDmp) | 52 | 0 / −16 | 52.000 / 51.984 |
| Total width T (ΔTs) | 16.25 | +200 / 0 | 16.450 / 16.250 |
Δdmp and ΔDmp: deviation of the mean bore and mean outside diameter in one radial plane. ΔTs: assembled width of cone and cup, from the ISO 492 table for metric tapered roller bearings. Cone width B and cup width C: 0 / −120 µm each.
Shaft and housing fits (general guidance)
For an inner ring that turns with a solid steel shaft under normal load, bearing makers’ fit tables give 20 k5 for the shaft of 30304. The cup usually sits in an H7 or J7 housing bore so that it can be moved when the pair is adjusted.
| Seat | Deviation, µm | Limits, mm | Fit with 30304 |
|---|---|---|---|
| Shaft 20 k5 | +11 / +2 | 20.011 / 20.002 | 2 to 23 µm interference |
| Housing 52 H7 | +30 / 0 | 52.030 / 52.000 | 0 to 46 µm clearance |
| Housing 52 J7 | +18 / −12 | 52.018 / 51.988 | 12 µm interference to 34 µm clearance |
Taking the loosest and the tightest combination of limits, a P0 30304 on a 20 mm k5 shaft has 2 to 23 µm interference. Its cup has 0 to 46 µm clearance in an H7 bore and 12 µm interference to 34 µm clearance in a J7 bore.
This is general guidance, not a FULI specification. Heavy or shock loads, a hollow shaft, a thin-walled, split or light-alloy housing, or a large temperature difference between shaft and housing call for other classes, and the drawing of your machine takes priority.
If the outer ring turns and the shaft stands still, as in an idler pulley or a wheel hub, the fits are reversed: the housing gets the interference fit (for example N7 or P7) and the shaft a sliding one (g6 or h6).
Sources: ISO 492 tables as printed in the NTN catalogue CAT. No. 2203/E (Tables 6.4 and 6.5) and the RKB tolerance catalogue; ISO 286-2 for the seats; SKF and NTN fit tables for the shaft and housing classes.
30304 compared with nearby sizes
30304 measures 20 × 52 × 16.25 mm: bore d, outside diameter D and total width T. Other tapered roller bearings on this site for the same 20 mm shaft are 32004 (20 × 42 × 15 mm), 30204 (20 × 47 × 15.25 mm) and 32204 (20 × 47 × 19.25 mm).
32204 is the lighter option on the same shaft, with an outside diameter 5 mm smaller (47 mm) and 3 mm more width (19.25 mm), for housings with less room. In FULI's catalog 32204 has a dynamic load rating of 30.30 kN against 33.10 kN and a weight of about 0.157 kg against 0.166 kg for 30304.
30205 has the same 52 mm outside diameter with a 25 mm bore, so it fits the same housing bore on a larger shaft.
32205 has the same 52 mm outside diameter with a 25 mm bore, so it fits the same housing bore on a larger shaft.
In the 303 series the sizes either side of 30304 are 30303 for a 17 mm shaft and 30305 for a 25 mm shaft.
| Model | Compared with this page | d × D × T (mm) | Cr (kN) | Weight (kg) |
|---|---|---|---|---|
| 30304 | This page | 20 × 52 × 16.25 | 33.10 | 0.166 |
| 30303 | Next size down | 17 × 47 × 15.25 | 28.30 | 0.129 |
| 30305 | Next size up | 25 × 62 × 18.25 | 46.90 | 0.266 |
| 32004 | Same bore | 20 × 42 × 15 | — | — |
| 30204 | Same bore | 20 × 47 × 15.25 | 28.20 | 0.126 |
| 32204 | Same bore | 20 × 47 × 19.25 | 30.30 | 0.157 |
| 30205 | Same outside diameter | 25 × 52 × 16.25 | 32.20 | 0.153 |
| 32205 | Same outside diameter | 25 × 52 × 19.25 | 41.30 | 0.2 |
Cr and weight from FULI's catalog; — = not listed on this site.
30304 weight, load ratings and speed
FULI's catalog gives the weight of 30304 as about 0.166 kg, so 100 bearings weigh about 16.6 kg and 1,000 about 166 kg before packing. The weight is for the cone and cup together.
30304 has a dynamic load rating Cr of 33.10 kN and a static load rating C0r of 33.20 kN. Cr is the load used to work out rating life; C0r is the reference for loads carried while the bearing is stationary or turning slowly.
Values from FULI's catalog; confirm for your application.
30304 cone and cup
30304 is supplied as a complete bearing: the cone (inner ring with rollers and cage) and the cup (outer ring). The total width T of 16.25 mm applies when the two are assembled; the cone and the cup on their own are each narrower. Tell us if you need only the cone or only the cup.
Tapered roller bearings carry radial load and axial load in one direction, so 30304 is normally mounted as one of a pair facing each other, and the end play or preload is set when the pair is adjusted on the shaft. That is why FULI lists the clearance as set during mounting, not as a C-class value.
30304 dimensions in inches
The nearest common inch shaft size to the 20 mm bore of 30304 is 13/16 in (20.64 mm), 0.64 mm larger than the bore, so 30304 will not go on it. Inch shafts need an inch bearing, not a metric one with a sleeve or shim.
| Dimension | Millimetres | Inches |
|---|---|---|
| Bore d | 20 mm | 0.7874 in |
| Outside diameter D | 52 mm | 2.0472 in |
| Total width T | 16.25 mm | 0.6398 in |
Converted at 1 in = 25.4 mm and rounded to four decimals. The bearing itself is made to the millimetre sizes.
Grease for 30304
FULI supplies tapered roller bearings rust-protected and normally without grease; grease is added when 30304 is mounted. Relubricating 30304 from the side takes about 4.23 g each time by the formula in our grease calculator: 0.005 × D × T = 0.005 × 52 × 16.25.
How FULI supplies 30304
The standard 30304 from FULI has GCr15 chrome steel rings and rollers and P0 precision, with P6 on request. Where an order states a requirement for the total width T (16.25 mm for 30304) or the cone height, each set is checked on a height gauge.
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 30304.
Tools and guides for 30304
- Bearing size finder: look up a size from bore, OD and width
- Bearing weight chart
- Bearing grease fill calculator
- Shaft and housing tolerance chart
- Tapered roller bearing number lookup
- Bearing lubrication basics
- Ball bearing vs roller bearing
- How to choose wheel hub bearings
- All bearing products and model pages
Typical applications
- Vehicle wheel hubs and axles
- Gearboxes and reducers
- Agricultural machinery
- Conveyor pulleys
FAQ
What is the difference between 30304 and 32204?
Both fit a 20 mm shaft. 30304 is 20 × 52 × 16.25 mm and 32204 is 20 × 47 × 19.25 mm, so 32204 has an outside diameter 5 mm smaller (47 mm) and 3 mm more width (19.25 mm). In FULI's catalog 32204 has a dynamic load rating of 30.30 kN against 33.10 kN and a weight of about 0.157 kg against 0.166 kg for 30304. 32204 suits a housing with less room; 30304 carries more load.
What size is 30304 in inches?
30304 is 0.7874 × 2.0472 × 0.6398 in (20 × 52 × 16.25 mm, d × D × T). The nearest common inch shaft size to the 20 mm bore of 30304 is 13/16 in (20.64 mm), 0.64 mm larger than the bore, so 30304 will not go on it. Use an inch bearing on an inch shaft.
How much does 30304 weigh?
About 0.166 kg in FULI's catalog, so 100 pieces weigh about 16.6 kg before packing. The weight is for the cone and cup together.
How much grease does 30304 need?
About 4.23 g each time it is relubricated from the side (0.005 × 52 × 16.25). FULI ships 30304 rust-protected without grease, so the first fill is made at mounting.
Is 30304 the same size across brands?
Bore d, outside diameter D and total width T are the same: 30304 is an ISO designation. The letters each maker adds (NSK HR and J, NTN 4T-, Koyo JR, FAG XL, SKF J2/Q) are series, design or cage codes, not seal codes. For 30304 the cone width B is not the same everywhere: 15 mm at NSK and Timken, 16 mm at NTN and Koyo.