Part number · Deep groove ball bearing
6321 Bearing – Size, Stock & Today’s Price
6321: a 105 × 225 × 49 mm deep groove ball bearing. Genuine SKF, FAG, NTN, NSK, KOYO and HCH, supplied across India with same or next-day delivery in Mumbai.
Deep groove ball bearing
- Bore (d)
- 105 mm
- Outside diameter (D)
- 225 mm
- Width (B)
- 49 mm
- Dynamic load rating (C)
- 182 kN
Available – ask for stock · Multiple brands
Prices change with brand, variant and quantity, so we quote today’s rate and reply during working hours.
The 6321 is a medium-series deep groove ball bearing with a 105 mm bore, a 225 mm outside diameter and a width of 49 mm. The 63 series is the heavy-duty choice for a given shaft: larger balls, a bigger outside diameter and more width than the 62, for higher loads and shock.
Its last two digits, 21, multiplied by 5 give the 105 mm bore. A full designation such as 6321-2RS-C3 means a 6321 with rubber seals on both sides and C3 internal clearance, the usual choice for electric motors.
Sharing the same 105 mm bore are the 6021 (105 × 160 × 26 mm), the 6221 (105 × 190 × 36 mm) and the 6821 (105 × 130 × 13 mm). They all fit a 105 mm shaft, but each needs a different housing, so check the outside diameter and width before you order.
Why 6321 prices vary
- Genuine or copy: fakes sell far below the real price and fail early. We sell only genuine bearings.
- Brand and origin: each maker, and each country of manufacture, is priced differently.
- Version: sealed, shielded, C3, stainless and low-noise versions cost more than the open bearing.
- Quantity: bulk and repeat orders are priced lower.
So we quote today’s price for each brand rather than list one number. Ask for the 6321 price on WhatsApp.
6321 dimensions
| Bore (d) | 105 mm |
|---|---|
| Outside diameter (D) | 225 mm |
| Width (B) | 49 mm |
Dimensions are the ISO 15 standard size, the same in every brand and seal type.
6321 load and speed ratings
| Dynamic load rating (C) | 182 kN |
|---|---|
| Static load rating (C₀) | 153 kN |
| Reference speed | 6,300 r/min |
| Limiting speed | 4,000 r/min |
Figures for the open SKF 6321 from SKF’s online catalogue (checked 9 Oct 2026). Other brands publish slightly different ratings for the same size. Sealed (2RS) versions have a lower limiting speed. SKF data sheet.
Other bearings for a 105 mm shaft
Same bore, different series: a bigger bearing carries more load but needs a bigger housing.
| Bearing | Size (mm) | Dynamic load C |
|---|---|---|
| 6021 | 105 × 160 × 26 | 76.1 kN |
| 6321 | 105 × 225 × 49 | 182 kN |
On a 105 mm shaft, the 6321 carries 139% more load than the slimmer 6021.
6321 variants
Every 6321 has the same outside dimensions. What changes is how it is sealed, its internal clearance and its material:
- 6321 (open): no shields or seals. For gearboxes and machines where oil or grease reaches the bearing.
- 6321 ZZ / 2Z: metal shields on both sides, greased for life. For clean, fast-running motors and fans.
- 6321 2RS: rubber seals on both sides (DDU at NSK, LLU at NTN). Better against dust and moisture.
- 6321 C3: internal clearance greater than normal, combined with any of the above (e.g. 6321-2RS-C3). The usual choice for electric motors.
- S6321 / SS6321: stainless steel for wet or corrosive conditions, usually marked with an S or SS prefix (SKF uses W). Supplied on request.
6321 equivalents by brand
Same size, written in each maker’s own style. Tap a brand to see how it numbers its bearings.
| Brand | Open | Shields | Seals | Seals + C3 |
|---|---|---|---|---|
| SKF | 6321 |
– |
– |
– |
| FAG | – |
– |
– |
– |
| NTN | 6321 |
6321ZZ |
6321LLU |
6321LLUC3 |
| NSK | 6321 |
6321ZZ |
6321DDU |
6321DDUC3 |
| KOYO | 6321 |
6321ZZ |
6321-2RS |
6321-2RS C3 |
| HCH | 6321 |
6321ZZ |
6321-2RS |
6321-2RS C3 |
Where the 6321 is used
- Large electric motors
- Industrial pumps and compressors
- Gearboxes and reducers
- Conveyor drives
- Machine tools
- Crushers, mixers and process plant
Brands available for 6321
Buying for a factory or workshop?
- GST invoice with every order
- One quotation for your whole list
- No minimum order
- Same or next-day delivery in Mumbai; dispatch across India
Is your 6321 genuine?
Counterfeit bearings are sold in many sizes and brands, including the 6321. Check that the marking on the ring matches the box exactly, that the brand’s own suffix style is used, and be wary of prices far below the market. How to spot a fake bearing.
Updated
Questions
6321 bearing: frequently asked
What size is a 6321 bearing?
A 6321 measures 105 mm bore × 225 mm outside diameter × 49 mm width. The size is the same in every brand and seal type.
What is the SKF, FAG or NSK equivalent of 6321 2RS C3?
NSK 6321DDUC3, NTN 6321LLUC3 and KOYO 6321-2RS C3. All are the same 105 × 225 × 49 mm size with rubber seals on both sides and C3 clearance.
Can I use a 6221 instead of a 6321?
Not without changing the housing. Both have a 105 mm bore, but the 6221 is 190 mm across and 36 mm wide, against 225 × 49 mm for the 6321.
What load can a 6321 bearing carry?
SKF rates the open 6321 at a dynamic load rating (C) of 182 kN and a static load rating (C0) of 153 kN, with a limiting speed of 4,000 r/min. Other brands publish similar figures. How much load it can carry in service also depends on speed, lubrication and the life you need.
Have a part number, or just a worn-out bearing?
Send it to us. We will tell you what it is, what it costs, and how soon it can be at your door.