NACHI 5208-2NS Double Row Angular Contact Ball Bearing, Double Sealed, 40x80x30.2 mm
Available
The NACHI 5208-2NS is a double row angular contact ball bearing with two contact seals (2NS), a 20° contact angle and a pressed steel cage. It measures 40 x 80 x 30.2 mm (bore x outer diameter x width) and carries a basic dynamic load rating of 40,000 N and a basic static load rating of 30,500 N.
A double row angular contact ball bearing is built like two single row bearings mounted back-to-back in one unit. It carries radial load, moment load and axial load in both directions, but because fewer balls fit in each row it has less load capacity than an equivalent back-to-back pair of single row bearings.
Where this product is used
- Pumps and compressors
- Gearboxes and speed reducers
- Shaft positions that need radial, moment and bidirectional axial load support from one bearing
- General industrial machinery
Features
- Two contact seals (2NS) close both sides of the bearing
- Two rows of balls at a 20° contact angle carry radial, moment and axial load in both directions
- Pressed steel cage
- Basic dynamic load rating 40 kN, static 30.5 kN
Key specifications
| Specification | Detail |
|---|---|
| Model | 5208-2NS |
| Type | Double row angular contact ball bearing |
| Bore d | 40 mm |
| Outer diameter D | 80 mm |
| Width B | 30.2 mm |
| Contact angle | 20° (no letter in the bearing number) |
| Cage | Pressed steel |
| Seals / shields | Two contact seals (2NS) |
| Basic dynamic load rating Cr | 40,000 N |
| Basic static load rating Cor | 30,500 N |
| Limiting speed, grease | 6,000 rpm |
| Mass | 0.57 kg |
| Chamfer r (min) | 1.1 mm |
| Shaft shoulder diameter da (min) | 47 mm |
| Housing shoulder diameter Da (max) | 73 mm |
| Fillet radius ra (max) | 1 mm |
Selecting the right option
Single or double row. A double row bearing takes radial, moment and bidirectional axial load in one housing position. A back-to-back pair of single row bearings has more load capacity for the same size, so check the loads against the ratings on this page.
Contact angle. This bearing has a 20° contact angle (no letter in the bearing number). A 30° version (letter A) also exists, but it is not part of this listing.
Sealed or open. A contact seal touches the inner ring, so it closes the bearing more fully against contamination than an open bearing does, at the cost of some friction. From the 5206 size up, the sealed type has lower load ratings than the open bearing of the same number and is rated for grease lubrication only.
Fitting and use
Check the load and speed against the figures in the table before ordering, and apply a suitable safety factor. Limiting speeds apply to lightly loaded bearings that are properly lubricated.
For a 20° double row bearing, the dynamic equivalent radial load is P = Fr + 1.09 Fa when Fa/Fr is 0.57 or less, and P = 0.70 Fr + 1.63 Fa above that. The static equivalent load is Por = Fr + 0.84 Fa.
The double row tables give a limiting speed for grease lubrication only for this type, and do not give a grease type or an operating temperature range, so check with AIMS before running close to the limit or at elevated temperature.
When fitting, apply force only through the ring that is being pressed on (the inner ring on a shaft, the outer ring in a housing), never through the other ring or the balls.
Related products
More sizes with the same closure are on NACHI double row angular contact bearings, 2NS sealed (8 sizes). Double row bearings with other closures: open (20 sizes), ZZ shielded, 25 to 70 mm bore (12 sizes) and ZZ shielded, 10 to 40 mm bore (6 sizes). For separate single row bearings used in pairs, see 15° flush-ground (28 sizes) and 40° (26 sizes).
Couldn't load pickup availability
Secure Checkout. We do not store credit card details
