Product sorting
List of products
55x120x29 mm
ZVL bearing with the complete designation NU 311 ZVL.
Metal shields on both sides
Greater radial internal clearance
55x120x29 mm
DKF bearing with the complete designation NUP 311 DKF.
55x120x29 mm
SKF bearing with the complete designation NU 311 ECJ SKF.
55x120x29 mm
URB bearing with the complete designation NU 311 E URB.
Practical advice
How to choose the right bearing
The same dimensions do not necessarily mean the same function. When selecting a replacement, check the construction, cover and seal design, internal clearance, and the conditions in which the bearing will operate.
Determine the type and size
Copy the full type designation. If missing, measure the inner diameter d, outer diameter D and width B.
Check the design
Distinguish open bearing, metal shields, and rubber seals. Also check internal clearance, accuracy, cage, and lubricant.
Take operating conditions into account
Rotational speed, direction, and magnitude of mechanical load, temperature, humidity, dust, and the method of installation are decisive.
How to read the type designation 6204 2RS C3
Suffixes may vary between manufacturers. When replacing, compare technical parameters, not just similar type designation.
Open, 2Z, or 2RS?
When are matching dimensions not enough?
A dimensionally identical bearing may have different load capacity, maximum speed, precision, or internal clearance. Pay special attention to electric motors, high temperatures, vibrations, shocks, and dusty or humid environments.
- radial, axial, and combined loads
- normal or increased internal clearance C3/C4
- operating temperature and maximum speed
- design of shields and seals, lubricant, cage material, and precision
Frequently asked questions
Can I replace a bearing with another brand?
Usually yes, if the design type, dimensions, internal clearance, precision, cover and seal design, load capacity, and allowable speeds match. The basic number alone is not enough; the meaning of the suffixes may vary according to the manufacturer.
How do I determine the diameter of the inner bore from the model designation?
For many common metric bearings, the bore diameter code from 04 is multiplied by five: for example, 04 = 20 mm and 06 = 30 mm. Codes 00 to 03 and some special designs have different rules, so it is advisable to verify the dimension.
Is 2RS better, or 2Z?
Neither is universally better. 2RS usually protects better against dirt and moisture, while 2Z tends to have lower friction and allows higher speeds. The right choice depends on the application.
What to send if the type designation is unreadable?
A photo of both sides, dimensions d × D × B, machine type, and information about speed, load, temperature, humidity, or dustiness. The more operational data we know, the more safely a replacement can be recommended.
Not sure about the replacement?
Send the type designation, dimensions, or a photo of the original part. We will help verify the suitable version before ordering.