6021-2RS bearing: complete specifications & equivalents
The 6021-2RS is a ISO 15 radial bearing sized 105 x 160 x 26 mm (bore x OD x width) with 2RS sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 105 mm |
| Outer diameter D | 160 mm |
| Width B | 26 mm |
| Material | GCr15 |
| Seal / shield | 2RS |
| Internal clearance | CN / C3 available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 76.1 kN |
| Basic static load rating C0 | 65.5 kN |
| Fatigue load limit Pu | 2.4 kN |
| Limiting speed (mechanical) | 2400 rpm |
| Operating temperature | -30 to +110 °C |
| Mass | 1650 g |
| Manufacturer designation | SKF 6021-2RS1 |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-24 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-24
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & 6000-series range
| Bore d | 4.134 in |
|---|---|
| Outer diameter D | 6.299 in |
| Width B | 1.024 in |
| ISO bore code | 21 |
| Radial section height (D−d)/2 | 27.5 mm |
| Smallest bore in 6000-series | 4 mm |
| Largest outer diameter in 6000-series | 1150 mm |
| Width range across 6000-series | 4–155 mm |
| Bore position in 6000-series (smallest first) | 28 of 61 |
| Bore above smallest 6000-series size | 101 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6021 | ISO 15 | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting. |
| 6021-2RS-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 6021-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 105×160×26 mm envelope per ISO 15; seal variant differs (2RS vs OPEN) — confirm sealing suits the duty. |
| 6021-RSR | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 105×160×26 mm envelope per ISO 15; seal variant differs (2RS vs RSR) — confirm sealing suits the duty. |
| 6021-ZZ-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 105×160×26 mm envelope per ISO 15; seal variant differs (2RS vs ZZ) — confirm sealing suits the duty. |
| 6021-M | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF 6021 M (machined brass cage, open arrangement) is the same-size execution on the 105×160×26 mm envelope with ratings within 10 % — boundary dimensions interchangeable. |
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 6021-2RS model number is decoded
In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6021 carries bore code 21 = 105 mm. Outside diameter 160 mm and width 26 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 105 mm shaft, typical catalogue practice is a m6 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. SKF's contact-seal catalogue number is 6021-2RS1 (older text: -2RS1), mapped here from the industry-neutral -2RS spelling.
Typical equipment & failure modes
Common applications
- heavy conveyors
- pulp and paper machinery
- medium and heavy industrial drives
- large 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)
- fretting corrosion on a loose shaft seat
- cage damage from operation beyond the limiting speed
Selection pitfalls — read before you substitute
- At 105 mm bore the ring mass is significant: heat 6021 on an induction heater (max 120 °C), never over an open flame, and plan puller access or a withdrawal sleeve now for the day it has to come off again.
- Choosing the 60xx extra-light section saves radial space at 105 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6221 before committing to the smaller envelope.
- Contact seals add drag and heat: 6021-2RS runs slower and cooler-limited than the open 6021; 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 6021-2RS: 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.
- The housing bore for the 160 mm OD should be round within IT7; an oval bore pinches the outer ring of 6021-2RS and shows up later as two-point loaded raceway wear.
- Measure the shaft, do not trust the drawing: a 105 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6021-2RS.
- SKF catalogues the contact-sealed version as 6021-2RS1 (older printings may read -2RS1); it is shipped pre-greased and its 2400 r/min limiting speed is set by seal-lip drag and grease life versus the open bearing's 8500 r/min thermal reference speed. The single-seal catalogue number is 6021-RS1, used where one shaft side needs external relubrication.
- A one-seal execution 6021-RS1 exists for arrangements that lubricate through the open side; fitting 6021-2RS1 instead means lifetime grease and no external oil supply — mixing the two in the same shaft can starve the sealed position.
- The 76.1/65.5 kN ratings here are SKF Explorer-class figures from catalogue PUB BU/P1 17000/1 EN (Oct 2018); SKF can revise internal geometry and ratings without changing the designation, so treat the catalogue version and date as part of the specification and re-verify for critical drives.
Frequently asked questions
What are the dimensions of a 6021-2RS bearing?
A 6021-2RS deep-groove ball bearing has a 105 mm bore, 160 mm outer diameter and 26 mm width (4.134 × 6.299 × 1.024 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased.
How does the 6000 compare with other series at the same 105 mm bore?
The second digit is the diameter series: 60 is the smallest standard section (160×26 mm, 27.5 mm radial section) at 105 mm bore — below 62/63/64 in load capacity, for light loads in compact spaces.
Are 6021 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 6021 uses the same ISO 15 envelope (105×160×26 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar).
What internal clearance does 6021-2RS have?
Unless a clearance suffix says otherwise, 6021-2RS 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 6021 and verify the residual clearance after mounting.
What is the SKF designation and catalogue data for 6021-2RS?
In the SKF Rolling Bearings catalogue this size is listed as 6021-2RS1 — two contact elastomer seals over a lifetime grease fill, 105×160×26 mm per ISO 15. Quoted values: C 76.1 kN, C0 65.5 kN, Pu 2.4 kN, limiting speed 2400 r/min, mass 1650 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 6021-2RS.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-24. Read our editorial & correction policy.