Deep groove ball bearings - Compact introduction to selection and use

1. Types of deep groove ball bearings

1.1 Single row deep groove ball bearings

Single-row deep groove ball bearings are the most commonly used bearing type. They can support radial and axial loads in both directions, operate at high speeds and are characterized by low frictional resistance.

Types:

• Open bearings:  Without seals, suitable for clean, oil-lubricated applications
• Z / 2Z:  With sheet steel cover plates on both sides, non-contact
• RS / 2RS:  With touching rubber seals, well suited for dusty or damp environments
• RZ / 2RZ:  With contactless rubber seals on both sides (low friction, better protection than Z)

Advantages:

• Cost-effective
• Low maintenance (sealed versions)
• Wide range of applications

Limits:

• Limited axial load carrying capacity compared to angular contact ball bearings

1.2  Double row deep groove ball bearings

Double-row designs correspond functionally to two single-row bearings, but have a more compact design.

Features:

• Significantly higher load-bearing capacity
• Ability to absorb radial, axial and tilting moments
• Less installation space than two individual bearings

Areas of application:

• Mechanical engineering
• Heavy-duty applications
• Kfz-Sector

2. bearing series and designs

2.1  Comparison of bearing series

The bearing series describes the relative width and load capacity of a bearing with the same bore diameter.

Series	Description	Construction width	Typical applications
618, 619	Particularly narrow bearings	Very narrow	Small appliances, model making
60	Normal series	Normal	Universal applications
62	Reinforced series	Wide	Industry, drive technology
63	Very reinforced series	Wider	Heavy machinery, agriculture
64	Extra wide bearing	Very wide	Heavy load, high impacts
160	Special series	Very wide	Special machines
42 (double row)	Comparable with 62	Compact	Wheel bearing, gearbox
43 (double row)	Comparable with 63	Compact	Highly loaded tilting moments

2.2 Designation system

Example: S 6205 2RS TN C3

Explanation of the components:

• S or SS = Stainless steel (stainless steel)
• 62 = Bearing series (reinforced series)
• 05 = Bore index (25 mm diameter)
• 2RS = Rubber seals in contact on both sides
• RZ = Contactless seal (less friction than RS, better protection than Z)
• TN / TVH =  Cage made of polyamide (glass fiber reinforced)
• C3 =  Bearing clearance greater than normal (for higher temperatures or speeds)

Bore index / diameter

Key figure	Diameter (mm)
00	10
01	12
02	15
03	17
04	20
05	25
06	30
07	35
08	40

3. load capacity and service life

3.1 Comparison of load ratings (d = 25 mm)

Series	Outer diameter (mm)	Dynamic C (kN)	Static C0 (kN)
619..	52	9,8	5,0
60..	47	11,1	6,0
62..	52	11,9	6,6
63..	62	19,5	10,0

3.2 Service life calculation

• Basic formula: L10 = (C/P)^3 × 10^6 Rotations
• P (dynamic load)
  • Fa / Fr ≤ e: P = Fr
  • Fa / Fr > e: P = X × Fr + Y × Fa

Example X/Y/e-Value:

Fa/C0	e	X	Y
0,3	0,22	0,56	2,0
1,6	0,32	0,56	1,4

3.3 Load limits

Load	Recommended limit	Note
Radial	Fr > C0 / 100	Avoid slippage damage
Axial	Fa ≤ 0,5 Fr	Higher values reduce service life
Setting angle	2'-16'	Varies depending on the bearing series

4. Seals

Seals	Type	Speed	Dust protection	Friction	Temperature range
open	-	Maximal	None	Very low	-30 °C bis +200 °C
Z/2Z	Cover disks	High	Middle	Low	-30 °C bis +120 °C
RZ/2RZ	Contactless rubber seal	High	Good	Low	-30 °C bis +110 °C
RS/2RS	Touching rubber	Middle	High	Middle	-30 °C bis +110 °C

5. Bearing clearance (radial clearance)

Class	Designation	Opening (d = 25 mm) [µm]
C2	Smaller than normal	1 - 11
CN	Normal	6 - 23
C3	Bigger than normal	18 - 36
C4	significantly bigger	30 - 51

6. temperature and speed limits

Bearing design	Material	Temperature range
Open, steel	Steel/brass	up to 200 °C
Sealed	PA66	-30 to +110 °C

Execution	Speed	Recommendation
open	100 %	Clean room, oil-lubricated
Z / 2Z	95 %	Low soiling
RZ / 2RZ	90 %	Good sealing at higher speeds
RS / 2RS	60 %	Dirty environment

7. Cage Variants

Cage type	Material	Advantages	Field of application
Sheet steel	Standard	Cost-effective	Standard bearing
Solid brass	Robust	Temperature resistant	Industry
Polyamid (TN/TVH)	Lightweight, low-noise	Inexpensive, vibration-damping	Electric motors, household appliances

8.  Areas of application

Industry	Application	Bearing Recommendation
Electrical industry	Motors, generators	CM-Bearing clearance, quiet bearing
White goods	Washing machines, fans	2RS, Grease lubricated
Mechanical engineering	Spindles, gearboxes	CN/C3, high precision
Agricultural technology	Harvesters	2RS, C3 Bearing clearance
Automotive industry	Auxiliary units	2RS, Low-noise

9. lubrication

Type	Medium	maintenance
open	Oil	Refill regularly
open	grease	Relubrication recommended
2Z	grease	Low maintenance
2RS	grease	No maintenance