NTN 21309CK spherical roller bearing
- Brand
- NTN
- Category
- Bearings
- Subcategory
- Spherical roller bearings
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Decoding NTN 21309CK
- 213Series
- Spherical roller bearings, 213 series. Series differ in outside diameter and width even when the bore is the same.
- 09Bore
- Bore 45 mm (09 × 5).
- CKSuffix
- NTN suffix: identifies the variant, such as seals or shields, cage, internal clearance or other features.
21309 is the standard ISO basic designation, which sets the bearing type, series and bore.
Description
NTN 21309CK measures 45 mm across the bore and 100 mm across the outside diameter; its width is 25 mm (45 x 100 x 25 mm).
NTN 21309CK belongs to spherical roller bearing, part of our Bearings range. Tell us how many you need by WhatsApp or email and we'll get back to you promptly with a quote for 21309CK and any equivalents.
The CK series from NTN covers self-aligning spherical roller bearings that carry two rows of rollers and come with a tapered bore. Because the outer ring can shift relative to the shaft, the bearing tolerates angular misalignment between shaft and housing, which suits drives, mining equipment, conveyors and other heavy machinery where deflection or imperfect mounting is a fact of life. MR Industrial Accessories LLC supplies this series to customers in the United States and Latin America.
Reading the designation helps when you order. The leading digits give the size and dimension series, while the CK suffix tells you the bore is tapered and the cage is made of sheet metal. Take 21308CK, 21309CK and 21310CK: all three carry the same suffix, yet bore diameter and load capacity differ from one to the next. A tapered bore also simplifies fitting on an adapter sleeve and lets you set internal clearance during mounting.
Typical duty includes gearboxes, mills, screens, conveyors, industrial fans and process equipment in cement, mining, steel, paper and food plants, where loads run high and alignment is rarely perfect. The self-aligning behavior is what makes the series a practical choice on long shafts or on shafts that flex under load.
Selection comes down to radial and axial load, operating speed and the surrounding environment. Sealing deserves attention: dusty or damp locations call for sealed or covered variants. Lubrication has to match the application, and with a tapered bore the radial clearance is controlled by how far the bearing advances axially. Careful initial alignment and correct fitting head off early failures.
Interchange is straightforward once you know what to compare. Spherical roller bearings with a tapered bore are identified by their numeric designation plus suffixes for cage, sealing or tolerance. Match the main dimensions, load capacity and bore type, and if you are holding another manufacturer's number, our team can point you to the equivalent.
Send the complete part number by WhatsApp or email and the team will come back with a quote. If you need a particular variant, include the exact model and we will help you confirm it.
Dimensions
45 x 100 x 25 mm (d x D x B): boundary dimensions for basic designation 21309, according to ISO 15.
- Bore
- 45 mm
- Outside diameter (D)
- 100mm
- Width (B)
- 25mm
SKF and other brands, same size
Other brands' pages with basic designation 21309: 45 x 100 x 25 mm (d x D x B) per ISO 15.
- Need the SKF 21309? We can also quote:21309 E21309 EK21309 E/C31 more →
- FAG21309-E1-XL21309-E1-XL-K
- NSK21309EAE421309EAKE4
- RKB21309
- TIMKEN21309EJ
What they share are the ISO 15 boundary dimensions, not the specs: seals or shields, internal clearance, cage and load rating may vary with brand and suffix. Every quote is by full part number.
Frequently asked questions
- NTN 21309CK bearing: what are its dimensions?
- NTN 21309CK measures 45 mm across the bore and 100 mm across the outside diameter; its width is 25 mm (45 x 100 x 25 mm). Those are the boundary dimensions standardized in ISO 15 for basic designation 21309.
- What does the CK suffix indicate on an NTN bearing?
- It signals a tapered bore together with a sheet metal cage. That combination eases mounting on a tapered shaft or with an adapter sleeve and allows internal clearance to be set. You will see it often in spherical roller bearings.
- In which equipment do CK series spherical roller bearings work?
- Gearboxes, mills, conveyors and heavy machinery are common homes for them, especially in cement, mining, steel and paper operations where loads are heavy and misalignment can appear.
- How do I get a quote for an NTN CK series bearing?
- Send the full part number, for instance 21308CK, through WhatsApp or email. If the reference is unclear, share a photo or the main dimensions and we will help identify it.