6306-2RS-FAG bearing: complete specifications & equivalents
The 6306-2RS-FAG is a ISO 15 radial bearing sized 30 x 72 x 19 mm (bore x OD x width) with 2RS sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | FAG |
| Bore diameter d | 30 mm |
| Outer diameter D | 72 mm |
| Width B | 19 mm |
| Material | GCr15 |
| Seal / shield | 2RS |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 32 kN |
| Basic static load rating C0 | 16.2 kN |
| Limiting speed (mechanical) | 9300 rpm |
| Mass | 343 g |
| Manufacturer designation | FAG 6306-C-2HRS |
| Standard | ISO 15 |
| Catalog version | HR 1 Rolling Bearings (Jan 2020) |
| Last verified | 2026-09-25 |
Source: catalog reference (HR 1 Rolling Bearings (Jan 2020)) · extracted 2026-09-25
Parameters extracted from the official FAG Rolling Bearings catalogue (HR 1 Rolling Bearings (Jan 2020)); FAG® is a trademark of Schaeffler Technologies AG & Co. KG, used here for identification only — mpnbase is not an authorized FAG/Schaeffler distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at schaeffler.com.
Dimensions in inches & 6300-series range
| Bore d | 1.181 in |
|---|---|
| Outer diameter D | 2.835 in |
| Width B | 0.748 in |
| ISO bore code | 06 |
| Radial section height (D−d)/2 | 21 mm |
| Smallest bore in 6300-series | 2 mm |
| Largest outer diameter in 6300-series | 500 mm |
| Width range across 6300-series | 3–95 mm |
| Bore position in 6300-series (smallest first) | 13 of 40 |
| Bore above smallest 6300-series size | 28 mm |
Mounting, lubrication & life for 6306-2RS-FAG
Recommended fits & mounting
- Rotating inner ring on a 30 mm shaft: k5; housing bore H7 for normal stationary-load outer rings. Reverse the logic if the outer ring rotates.
- Fit by induction heating (max 120 °C) where practical — never drive the ring home through the rolling elements.
- Keep shaft and housing fillet radii below the bearing chamfer so the 19 mm-wide ring seats square on its shoulder.
Lubrication strategy
Contact-sealed execution: greased and sealed for life, no relubrication path. Grease life — not steel fatigue — usually sets the replacement interval; rising running temperature or noise near the end of service is the practical trigger.
Worked L10 life example (illustrative duty)
For ball bearings, L10h = (C/P)3 · 106 / (60·n). Taking an example radial equivalent load P = 3 kN at n = 1,500 r/min (a small belted motor duty — substitute the real equivalent load from the application calculation):
C = 32.0 kN → L10h ≈ 13,485 hours
Choosing a section at the same 30 mm bore
| Series | Open execution | OD × width | C (kN) | Limiting speed (r/min) |
|---|---|---|---|---|
| 60xx | 6006-FAG | 55 × 13 | 14.5 | 20,100 |
| 62xx | 6206-FAG | 62 × 16 | 22.0 | 17,800 |
| 63xx | 6306-FAG | 72 × 19 | 32.0 | 15,100 |
| 64xx | 6406-FAG | 90 × 23 | 42.5 | 11,000 |
| 618xx | 61806-FAG | 42 × 7 | 4.5 | 24,500 |
| 619xx | 61906-FAG | 47 × 9 | 7.2 | 21,700 |
| 160xx | 16006 | 55 × 9 | 11.2 | 18,500 |
A larger section is not a drop-in swap — OD and width change — and same-envelope seal variants are compared on the 30×72×19 envelope page. Match meaning, not the size chart alone: see what the cross-reference levels mean.
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6306-2RS-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6306-RSR-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6306-ZZ-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6306-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6306-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6306-2RS-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6306-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6306-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6306 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6306-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6306-2RS | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 6306-RSR | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| W6306-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| W6306-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| W6306 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 306 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 306-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the 6306-2RS-FAG model number is decoded
6306-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 06 by five gives the 30 mm bore; the 72 mm outside diameter and 19 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 30 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. Schaeffler HR 1 catalogues the lip-contact sealed version as 6306-C-2HRS (FAG suffix 2RSR), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.
Typical equipment & failure modes
Common applications
- fans and blowers
- electric motors
- centrifugal pumps
- small gearboxes
Known failure patterns
- seal-lip hardening and loss of pre-grease in sustained high-temperature service
- grease-life expiry in the sealed-for-life cavity (no relubrication path)
- raceway smearing under marginal lubrication at start-up
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- At a 30 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6306-2RS-FAG; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.
- The 63xx medium section at 30 mm bore gains dynamic rating through larger rolling elements on a 72 mm OD; the penalty is mass and a lower limiting speed than the 6206 — do not specify it for speed-critical shafts.
- Contact seals add drag and heat: 6306-2RS-FAG runs slower and cooler-limited than the open 6306; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.
- Heat is the enemy of the sealed 6306-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.
- Suffixes stack in a defined order — clearance follows the seal code, e.g. 6306-2RS-FAG-C3. No clearance suffix means normal CN clearance.
- Do not quieten a noisy bearing by preloading it: the 6300-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.
- Schaeffler HR 1 lists the lip-contact sealed version as 6306-C-2HRS (FAG suffix 2RSR), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing. FAG's RSR lip material is NBR as standard — above roughly 100 °C continuous, consult Schaeffler for higher-temperature seal options.
- At 9300 r/min mechanical limiting speed, 6306 covers general-purpose motor and pump duty; keep grease fill at 25–35% of free volume and verify the housing can dissipate the frictional heat at the thermal reference speed.
- The 30 mm bore puts 6306 in Schaeffler's light industrial range; the standard cage and CN clearance cover most fractional-horsepower motor and small-pump duty, and FAG's X-life generation of these sizes carries higher ratings than legacy HR 1 printings — check the current eKatalog listing before reordering.
- At 32 kN dynamic load rating (C) and 16.2 kN static (C0), 6306 is a medium-load FAG bearing for most electric-motor and pump duty; check the static safety factor against C0 for preloaded or thrust-loaded arrangements.
- At 343 g, 6306 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.
- The 30×72×19 mm envelope of 6306 gives a D/d ratio of 2.40 and 21.0 mm radial section height — a heavy FAG section for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.
- The 32/16.2 kN load ratings, mass 343 g here are Schaeffler HR 1 Rolling Bearings (Jan 2020) catalogue figures for 6306-C-2HRS on the 30×72×19 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6306 in a rated drive. Where FAG has since released an X-life version of this size, its expanded C/C0 ratings supersede the HR 1 print values quoted here.
- For hot shafts above roughly 100 °C continuous, consult Schaeffler about seal material and grease options for the 2RSR execution of 6306; the standard NBR lip is the economical general-duty choice, not the high-temperature one.
- Schaeffler has moved many HR 1 sizes to the X-life generation with higher C/C0 ratings; the designation is unchanged, so a current eKatalog listing for 6306 may quote higher values than the HR 1 print figures on this page — the envelope is identical either way.
Frequently asked questions
What are the dimensions of a 6306-2RS-FAG bearing?
A 6306-2RS-FAG deep-groove ball bearing has a 30 mm bore, 72 mm outer diameter and 19 mm width (1.181 × 2.835 × 0.748 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased.
What internal clearance does 6306-2RS-FAG have?
Unless a clearance suffix says otherwise, 6306-2RS-FAG is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6306 and verify the residual clearance after mounting.
How should 6306-2RS-FAG be mounted?
Apply the mounting force to the ring being fitted: on a 30 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals.
What is the FAG suffix for a sealed 6306?
FAG uses suffix 2RSR for the lip-contact rubber seal (catalogue number 6306-C-2HRS), 2RZ for the non-contact rubber seal and 2Z for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those FAG suffixes while keeping the 30×72×19 mm ISO 15 envelope.
Does FAG offer 6306 with C3 clearance?
FAG lists C3 internal clearance for most deep-groove sizes (suffix C3 follows the seal code); choose C3 for tight fits or hot shafts and stay with the standard CN clearance of 6306-C-2HRS for normal duty.
Reviewed & verified by the MPN Base engineering desk against source catalog HR 1 Rolling Bearings (Jan 2020) on 2026-09-25. Read our editorial & correction policy.