Table 3-1 Recommended bearing service life

Operating condition Application Recommended
service life (h)
Short or intermittent operation Household electric appliance, electric tools,agricultural equipment, heavy cargo hoisting equipment
4,000
to
 8,000
Not extended duration, but stable operation required Household air conditioner motors,construction equipment, conveyers, elevators
8,000
to
 12,000
Intermittent but extended operation Rolling mill roll necks, small motors,cranes
8,000
to
 12,000
Motors used in factories, general gears
12,000
to
 20,000
Machine tools, shaker screens, crusher
20,000
to
 30,000
Compressors, pumps, gears for essential use
40,000
to
 60,000
Daily operation more than 8 hrs. or continuous extended operation Escalators
12,000
to
 20,000
Centrifugal separators, air conditioners, air blowers, woodworking equipment,passenger coach axle journals
20,000
to
 30,000
Large motors, mine hoists, locomotive axle journals, railway rolling stock traction motors
40,000
to
 60,000
Paper manufacturing equipment
100,000
to
 200,000
24 hrs. operation (no failure allowed) Water supply facilities, power stations, mine water discharge facilities
100,000
to
 200,000