6307 Bearing Dimensions
6307 is a deep groove ball bearing with a 35 mm bore, 80 mm outer diameter and 21 mm width (35×80×21 mm, ISO 15). Open, ZZ, 2RS variants, designation breakdown, size-equivalent codes. Quote.
6307 specifications
| Bore d | 35 mm |
|---|---|
| Outside diameter D | 80 mm |
| Width B | 21 mm |
| Seal / shield options | Open; ZZ (two metal shields); 2RS (two rubber seals) |
| Material | GCr15 chrome bearing steel (rings and rolling elements) |
| Precision | P0 (standard); P6 on request |
| Vibration grade | Z3V3 (standard); other grades on request |
| Radial clearance | C0 (standard); C3 on request |
Load ratings & speed
| Dynamic load rating Cr | 30.15 kN |
|---|---|
| Static load rating C0r | 18.34 kN |
| Limiting speed, grease | 8,400 rpm |
| Limiting speed, oil | 9,500 rpm |
| Weight | 0.464 kg — approx. |
Values from FULI's catalog; confirm for your application.
Nearby 6300 series sizes: 6305 bearing · 6306 bearing · 6308 bearing · 6309 bearing
Grease quantity for 6307: bearing grease fill calculator.
Buying 6307 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 6307 designation
| Segment | Meaning |
|---|---|
| 6 | Single row deep groove ball bearing |
| 3 | Dimension series 03 (medium) |
| 07 | Bore code 07 → 35 mm bore. ISO bore code (00–03 = 10/12/15/17 mm; 04 and above = code × 5 mm). |
6307 cross reference by brand
The basic number 6307 means the same boundary dimensions at every maker listed here (35 × 80 × 21 mm). The suffix for shields, seals and clearance is written differently by each maker.
| Version | FULI | SKF | Timken | NSK | NTN | Koyo | NACHI |
|---|---|---|---|---|---|---|---|
| Open | 6307 | 6307 | 6307 | 6307 | 6307 | 6307 | 6307 |
| Shields both sides | 6307ZZ | 6307-2Z | 6307-ZZ | 6307ZZ | 6307ZZ | 6307 ZZ | 6307ZZE |
| Contact seals both sides | 6307-2RS | 6307-2RS1 | 6307-2RS | 6307DDU | 6307LLU | 6307 2RS | 6307-2NSE |
| Contact seals + C3 | 6307-2RS C3 | 6307-2RS1/C3 | 6307-2RS-C3 | — | — | — | — |
— = ask us. FULI radial clearance is C0 as standard and C3 on request.
SKF cross reference · Timken and Fafnir cross reference · NSK, NTN, Koyo and NACHI cross reference · Suffix meanings
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 6307
FULI makes 6307 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 35 × 80 × 21 mm size.
| Dimension | Nominal, mm | Deviation, µm | Limits, mm |
|---|---|---|---|
| Bore d (Δdmp) | 35 | 0 / −12 | 35.000 / 34.988 |
| Outside diameter D (ΔDmp) | 80 | 0 / −13 | 80.000 / 79.987 |
| Width B (ΔBs) | 21 | 0 / −120 | 21.000 / 20.880 |
Δdmp and ΔDmp: deviation of the mean bore and mean outside diameter in one radial plane. ΔBs: inner ring width; the outer ring width has the same limits.
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 35 k5 for the shaft of 6307. The housing bore is usually H7, or J7 where the outer ring must not creep.
| Seat | Deviation, µm | Limits, mm | Fit with 6307 |
|---|---|---|---|
| Shaft 35 k5 | +13 / +2 | 35.013 / 35.002 | 2 to 25 µm interference |
| Housing 80 H7 | +30 / 0 | 80.030 / 80.000 | 0 to 43 µm clearance |
| Housing 80 J7 | +18 / −12 | 80.018 / 79.988 | 12 µm interference to 31 µm clearance |
Taking the loosest and the tightest combination of limits, a P0 6307 on a 35 mm k5 shaft has 2 to 25 µm interference. Its outer ring has 0 to 43 µm clearance in an H7 bore and 12 µm interference to 31 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. A tight shaft fit or a hot housing uses up internal clearance, and that is when C3 is chosen instead of C0.
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.
6307 compared with nearby sizes
6307 measures 35 × 80 × 21 mm: bore d, outside diameter D and width B. Other deep groove ball bearings on this site for the same 35 mm shaft are 6807 (35 × 47 × 7 mm), 6907 (35 × 55 × 10 mm), 16007 (35 × 62 × 9 mm), 6007 (35 × 62 × 14 mm), 6207 (35 × 72 × 17 mm) and 6407 (35 × 100 × 25 mm).
6407 is the next heavier choice for a 35 mm shaft, with an outside diameter 20 mm larger (100 mm) and 4 mm more width (25 mm). In FULI's catalog 6407 has a dynamic load rating of 55.00 kN against 30.15 kN and a weight of about 0.952 kg against 0.464 kg for 6307.
6207 is the lighter option on the same shaft, with an outside diameter 8 mm smaller (72 mm) and 4 mm less width (17 mm), for housings with less room. In FULI's catalog 6207 has a dynamic load rating of 23.13 kN against 30.15 kN and a weight of about 0.284 kg against 0.464 kg for 6307.
6208 has the same 80 mm outside diameter with a 40 mm bore, so it fits the same housing bore on a larger shaft.
6405 has the same 80 mm outside diameter with a 25 mm bore, so it fits the same housing bore on a smaller shaft.
In the 63 (medium) series the sizes either side of 6307 are 63/32 for a 32 mm shaft and 6308 for a 40 mm shaft.
| Model | Compared with this page | d × D × B (mm) | Cr (kN) | Weight (kg) |
|---|---|---|---|---|
| 6307 | This page | 35 × 80 × 21 | 30.15 | 0.464 |
| 63/32 | Next size down | 32 × 75 × 20 | 26.82 | 0.389 |
| 6308 | Next size up | 40 × 90 × 23 | 36.45 | 0.636 |
| 6807 | Same bore | 35 × 47 × 7 | 4.41 | 0.027 |
| 6907 | Same bore | 35 × 55 × 10 | 10.08 | 0.075 |
| 16007 | Same bore | 35 × 62 × 9 | 10.53 | 0.107 |
| 6007 | Same bore | 35 × 62 × 14 | 14.40 | 0.151 |
| 6207 | Same bore | 35 × 72 × 17 | 23.13 | 0.284 |
| 6407 | Same bore | 35 × 100 × 25 | 55.00 | 0.952 |
| 6208 | Same outside diameter | 40 × 80 × 18 | 26.19 | 0.366 |
| 6405 | Same outside diameter | 25 × 80 × 21 | 34.50 | 0.530 |
Cr and weight from FULI's catalog; — = not listed on this site.
6307 weight, load ratings and speed
FULI's catalog gives the weight of 6307 as about 0.464 kg, so 100 bearings weigh about 46.4 kg and 1,000 about 464 kg before packing. The open, ZZ and 2RS versions share this catalog line.
6307 has a dynamic load rating Cr of 30.15 kN and a static load rating C0r of 18.34 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. Limiting speeds in the catalog are 8,400 rpm with grease and 9,500 rpm with oil.
Contact seals add friction at the lip, so 6307-2RS usually runs below the speed of the open bearing. Ask us for the limit of the version you order.
Values from FULI's catalog; confirm for your application.
6307 versions: open, ZZ, 2RS and C3
Every version of 6307 has the same 35 × 80 × 21 mm boundary dimensions; only the cover between the rings and the internal clearance change. FULI supplies open, ZZ and 2RS versions, with C0 clearance as standard and C3 on request. Other makers write the same covers as 2Z or ZZ for shields and 2RS1, DDU or LLU for contact seals.
| Designation | What it is | Typical choice |
|---|---|---|
| 6307 | Open, no shields or seals | Housings with their own oil or grease supply |
| 6307-ZZ | Two metal shields, non-contact, greased | Motors and fans where dust is light |
| 6307-2RS | Two rubber contact seals, greased | Pumps, farm machinery and other wet or dusty places |
| 6307-ZZ C3 | ZZ with the larger C3 radial clearance | Tight shaft fit or a housing that runs hot |
| 6307-2RS C3 | 2RS with C3 radial clearance | Sealed bearings on a tight fit or running hot |
6307 dimensions in inches
The nearest common inch shaft size to the 35 mm bore of 6307 is 1-3/8 in (34.93 mm), 0.07 mm smaller than the bore, so 6307 would be loose on it. Inch shafts need an inch bearing, not a metric one with a sleeve or shim.
| Dimension | Millimetres | Inches |
|---|---|---|
| Bore d | 35 mm | 1.3780 in |
| Outside diameter D | 80 mm | 3.1496 in |
| Width B | 21 mm | 0.8268 in |
Converted at 1 in = 25.4 mm and rounded to four decimals. The bearing itself is made to the millimetre sizes.
Grease for 6307
FULI fills sealed 6307-2RS and 6307-ZZ bearings to about 30% of the free internal space as standard. The fill is set on an automatic greasing machine after sample sets are weighed before and after greasing. In normal use, sealed bearings usually do not need regreasing. A different fill level, a low-noise grease or a grease for a stated temperature range can be written on the order; for North America a range of −40 to 120 °C is often asked for.
Relubricating 6307 from the side takes about 8.40 g each time by the formula in our grease calculator: 0.005 × D × B = 0.005 × 80 × 21. This applies to the open 6307 in a housing with a grease supply.
How FULI supplies 6307
The standard 6307 from FULI has GCr15 chrome steel rings and balls, P0 precision, C0 radial clearance and vibration grade Z3V3; P6, C3 and other vibration grades are made on request. Radial clearance is set on automatic assembly equipment and sampled during production. Orders with a noise or vibration requirement are tested set by set before packing.
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 6307-2RS C3.
Tools and guides for 6307
- Bearing size finder: look up a size from bore, OD and width
- Bearing weight chart
- Bearing grease fill calculator
- Shaft and housing tolerance chart
- Open, ZZ or 2RS seal selector
- Bearing internal clearance: C0, C3 and when to change
- Bearing lubrication basics
- Noise grade and precision class
- Ball bearing vs roller bearing
- All bearing products and model pages
Typical applications
- Electric motors
- Fans and blowers
- Water pumps
- Gearboxes
- Agricultural and textile machinery
FAQ
What is the difference between 6307 and 6407?
Both fit a 35 mm shaft. 6307 is 35 × 80 × 21 mm and 6407 is 35 × 100 × 25 mm, so 6407 has an outside diameter 20 mm larger (100 mm) and 4 mm more width (25 mm). In FULI's catalog 6407 has a dynamic load rating of 55.00 kN against 30.15 kN and a weight of about 0.952 kg against 0.464 kg for 6307. Choose 6407 for a higher load where the housing has room for it; 6307 keeps the housing smaller.
What is the difference between 6307 and 6207?
Both fit a 35 mm shaft. 6307 is 35 × 80 × 21 mm and 6207 is 35 × 72 × 17 mm, so 6207 has an outside diameter 8 mm smaller (72 mm) and 4 mm less width (17 mm). In FULI's catalog 6207 has a dynamic load rating of 23.13 kN against 30.15 kN and a weight of about 0.284 kg against 0.464 kg for 6307. 6207 suits a housing with less room; 6307 carries more load.
What size is 6307 in inches?
6307 is 1.3780 × 3.1496 × 0.8268 in (35 × 80 × 21 mm, d × D × B). The nearest common inch shaft size to the 35 mm bore of 6307 is 1-3/8 in (34.93 mm), 0.07 mm smaller than the bore, so 6307 would be loose on it. Use an inch bearing on an inch shaft.
How much does 6307 weigh?
About 0.464 kg in FULI's catalog, so 100 pieces weigh about 46.4 kg before packing. The open, ZZ and 2RS versions share this catalog line.
What is the difference between 6307-ZZ and 6307-2RS?
Both are 35 × 80 × 21 mm, the same as the open 6307. 6307-ZZ has two metal shields that do not touch the inner ring, so it runs with little drag but only keeps out coarse dirt. 6307-2RS has two rubber seals whose lips touch the inner ring; it keeps out water and fine dust at the cost of more friction. FULI fills both to about 30% of the free space.
How much grease does 6307 need?
Sealed 6307-2RS and 6307-ZZ come filled to about 30% of the free space and in normal use usually do not need regreasing. An open 6307 relubricated from the side takes about 8.40 g each time (0.005 × 80 × 21).
Is 6307 the same size across brands?
Yes. 6307 is an ISO designation, so the bore, outside diameter and width are the same whichever manufacturer made it. Brand-specific suffixes only change details such as seals, clearance or cage.