The chart below is designed to give an overview of the balance quality grades for various groups of representative rigid rotors.
Note: Some groups of rotors, not included in the official ISO table, are added and reported in Italic type form.
Balancing quality grade is show in G mm/s
Spindles, discs and armatures of precision grinders
1,0 Small electric armatures with special requirements
Tape recorder and phonograph (gramophone) drives, cine projectors
Grinding machine drives
Turbines and Compressors with special requirements
2,5 Gas and steam turbines, including marine main turbines (merchant service)
Turbine driven pumps
Rigid turbo generator rotors
High speed compressors and aeronautic compressors
Medium and large electric armatures with special requeriments
High quality household electric armatures, dentist drills and textile components
Small electric armatures not qualifying for one or both of the conditions specified
for small electric armatures of balancing quality grade G 6,3
Machine tool drive
Air conditioning fans for hospitals and concert halls
High speed gears(over 1000 RPM) of marine turbines .
Computer memory drums and discs
6,3 Small electric armatures, often mass produced, in vibration insensitive applications, and/or
with vibration isolating mountings.
Medium and large electric armatures (of electric motors having at least 80 mm shaft height )
without special requirements
Machine tool and general machinery parts
Parts of process plant machines, Centrifuge drums, decanters, washers
Hydraulic machine rotors
Fly wheels, Fans; Pump impellers
Marine main tuebine gears (merchant service )
Paper machinery rolls; print rolls
Assembled aircraft gas turbine rotors
Individual components of engines under special requirements
16 Drive shafts (propeller shafts, cardan shafts) with special requirements
Parts of agricultural machinery, parts of crushing machines
Individual components of engines (gasoline or diesel) for cars ,trucks and locomotives
Crankshaft / drives of engines with six or more cylinders under special requirements
Low speed separators
Light boat impellers)
Motor bicycle and car wheels
Normal transmission pulley
Wood machine tools
40 Car wheels, wheel rims, wheel sets and drive shafts
Crankshaft / drives of elastically mounted fast four cycle engines (gasoline or diesel ) with
six or more cylinders (pistons speed greater than 9 m/s)
Crankshaft /drives of engines of cars , trucks and locomotives
We hope that you will find this information useful - please get in touch with the specialist balancing team at Cemb Hofmann UK on 0161 872 3123 should you have any queries regarding this table or any other aspect of balancing.
Please visit our site: www.cembhofmann.co.uk for more information about balancing machines and sub contract balancing services.