Brush Grade Primer

Carbon brushes come in the following grade classes:

C or CG
Type : Carbon (carbon graphite)
Appearance : Chalky gray or black
Speed : Low
Current : Low
Voltage : Medium
Application : For old flushmica commutators


E or EG
Type : Electrographite
Appearance : Hard black with no or little dust residue
Speed : High
Current : High
Voltage : High
Application : Most new motors

G
Type : Graphite
Appearance : Silvery like a pencil lead
Speed : Very high
Current : Low
Voltage : Medium
Application : Low friction

M or MG
Type : Metal graphite
Appearance : Silvery and possile copper color
Speed : Medium
Current : Very High
Voltage : Low
Application : Low resistance 12V and 24V

Ag
Type : Silver graphite
Appearance : Silvery and maybe grainy
Speed : Medium
Current : Very high
Voltage : Low
Application : Tachometers