ISO Quality Grades

Balance quality grade G

ew 1] 2] mm/s

Rotor Types - General examples

G 40

40

- Car wheels, wheel rims, wheel sets, drive shafts.
- Crankshaft-drives of elastically mounted fast four-cycle engines (gasoline or diesel) with six or more cylinders4).
- Crankshaft-drives for engines of cars, trucks and locomotives.

G 16

16

- Drive Shafts (propeller shafts, cardanshafts with special req
- Parts of crushing machinery.
- Parts of agricultural machinery.
- Individual components of engines (gasoline or diesel) for cars, trucks and locomotives.
- Crankshaft-drives of engines with six or more cylinders under special requirements.

G 6,3

6,3

- Parts or process plant machines.
- Marine main turbine gears (merchant service).
- Centrifugal drums.
- Fans
- Assembled aircraft gas turbine rotors.
- Fly wheels.
- Pump impellers.
- Machine-tool and general machinery parts.
- Normal electrical armatures.
- Individual components of engines under special requirements.

G 2,5

2,5

- Gas and steam turbines, including marine turbines (merchant service).
- Rigid turbo-generator rotors.
- Rotors.
- Turbo-compressors.
- Machine-tool drives.
- Medium and large electrical armatures with special requirements.
- Small electrical armatures.
- Turbine-driven pumps.

G 1

1

- Tape recorder and phonographs (gramophone) drives.
- Grinding-machine drives.
- Small electrical armatures with special requirements

G 0,4

0,4

- Spinles, disks and armatures of precision grinders.
- Gyroscopes.

1] w=2xn / 60-N / 0, if n is measured in revolutions per minute and w in radians per second. To simplify: Tolerance = Component Weight [kg] x Quality Grade x 9549 / Operational Speed [RPM]

2] In general, for rigid rotors with two correction planes, one-half of the recommended residual unbalance is to be taken for each plane.