Gear quality class according to its application.

 

Gear quality class according to its application.

Application of gear	DIN Class
Control gears	2 - 4
Measuring instruments	3 - 6
Turbine reducers	3 - 5
Aviation reducers	3 - 6
Machine tools	3 - 7
Aviation engines	5 - 6
High speed gearboxes	5 - 6
Passenger cars	6 - 7
Industrial gearboxes	7 - 8
Light ship engines	7
Two Wheeler (mass production)	8-9
Rolling mills, locomotives	8 - 9
Heavy ship engines, tractors, truck	8 - 9
Building and agricultural machines	8 - 10
Textile machines	7 - 9

This List for reference only , however designer can change Gear quality class as per application and noise required .