31320 Tapered Roller Bearing (100x215x56.5mm)
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Bearing dimensions and basic technical information.
Dimension Notes
For tapered roller bearings the width above is the overall width T = 56.5 mm. The inner-ring width B (and the cup width C) are printed by each manufacturer and appear with the brand values below.
Manufacturer Ratings
Load-rating symbols are printed as each manufacturer writes them in its own catalogue, so the same quantity can carry a different symbol from brand to brand.
| Brand | Dynamic Load Rating | Static Load Rating | Fatigue Load Limit | Additional Data |
|---|---|---|---|---|
| SKF 31320 X | 399 kN | 465 kN | 51 kN | — |
| NSK HR31320J | 475 kN | 505 kN | — | — |
| Schaeffler (FAG) 31320-X-XL | 450 kN | 480 kN | 67 kN | — |
| NTN 31320XU | 395 kN | 435 kN | 46 kN | — |
| Timken 31320X | 416 kN | 526 kN | — | Dynamic Radial Rating, 90×10⁶ rev (C90): 108 kN · Dynamic Thrust Rating, 90×10⁶ rev (Ca90): 152 kN · Geometry Factor (Cg): 0.12 |
Speed Ratings
Speed limits depend on sealing and lubrication, and definitions differ by manufacturer. Contact-sealed variants are normally greased for life and run slower. Always confirm the exact variant in the manufacturer's table.
| Brand | Grease open / shielded | Oil open | Reference | Limiting |
|---|---|---|---|---|
| SKF 31320 X | — | — | 2,200 r/min | 3,000 r/min |
| NSK HR31320J | 1,500 r/min | 2,200 r/min | — | — |
| Schaeffler (FAG) 31320-X-XL | — | — | 2,550 r/min | 3,850 r/min |
| NTN 31320XU | 1,800 r/min | 2,400 r/min | — | — |
| Timken 31320X | — | — | — | — |
References
- SKF — SKF Group, Rolling Bearings, PUB BU/P1 17000/1 EN, Oct. 2018.
- NSK — NSK Ltd., Rolling Bearings for Industrial Machinery, CAT. No. E1103, Tokyo, Japan, Jan. 2025.
- Schaeffler (FAG) — Schaeffler Technologies AG & Co. KG, Rolling Bearings, HR 1, Herzogenaurach, Germany, Feb. 2025.
- NTN — NTN Corporation, Ball and Roller Bearings, CAT. No. 2203-3E, Osaka, Japan, Sep. 2000.
- Timken — The Timken Company, Tapered Roller Bearing Catalog, North Canton, OH, USA.
About This Type
Tapered roller bearings carry combined radial and axial loads in one axial direction. Because a radial load induces an axial component, they are almost always mounted in opposed pairs. Typical applications include vehicle wheel hubs, gearboxes and differentials, conveyor rollers, agricultural and construction machinery, and machine-tool spindles.
Because a single bearing carries axial load in one axial direction only, two bearings are mounted back-to-back or face-to-face so that each carries the axial load in its own axial direction. For a given bore size, a heavier dimension series (for example 303 instead of 302) provides higher load ratings at the cost of limiting speed and envelope size, while a large-contact-angle series such as 313 is chosen when the axial share of the load is high. The CN/C2/C3 radial-clearance groups do not apply to single-row tapered roller bearings: running clearance or preload is set by the mounting adjustment, not by a clearance suffix.
The cone (inner ring with rollers) and the cup (outer ring) are separable and are mounted separately. Axial clearance or preload is set during installation — by shims, a shaft nut, or a threaded adjustment — and largely determines bearing life: too loose runs noisily and wears faster; too tight overheats. Cones and cups are matched sets; do not interchange parts between bearings, and recheck the setting after the first few hours of operation.
Series note: The 313 series has a large contact angle for high axial loads; the large axial force component makes a paired (usually face-to-face) arrangement essential.
Related Guides
Disclaimer: Data on this page is compiled from publicly available online sources for reference only, and not every model appears in a manufacturer's published catalog. Values may differ between sources and editions — always verify against the manufacturer's current documentation before design or purchase.Full disclaimer →