How to Select Your Brush DC Motor

Selection Criteria

Motor diameter

Sizing a brush DC motor to a specific application begins with matching the motor's diameter to the available space. In general, larger frame size motors deliver more torque. Motor diameter ranges from 8 mm to 35 mm.


Various lengths are available, ranging from 16.6 mm to 67.2 mm, to best fit the application package requirements.

Commutation type

Precious metal brushes are well adapted to low current density applications, providing low friction and high efficiency, whereas high continuous or peak current applications will require graphite-copper brushes.

Bearing type

Several bearing combinations have been designed, from simple sleeve bearing construction to preloaded ball bearings systems for high axial or radial load applications.

Magnet and commutation type

Adapt your motor selection to the power and current needs of your application: NdFeB magnets provide higher output torque than Alnico, at a higher cost. The commutation system (type and size of the commutators) is also reflected in this coding.


Various winding options are proposed to best match with the application requirements – voltage, resistance and torque constant are the basic parameters for selection.

Execution code

Used to specify standard and customizations.

 Brush DC
 35 N T 2R 82 426E 50
35  Diameter
N Motor generation / length
L,C = Old generation (C-short, L-long)
S, N, V = Middle generation (S-short, N-normal, V-very long)
G, GS = New generation, high power magnet (S-short version)
T Commutation type
Blank = precious metal
T = graphite
 2R Bearing type
Blank = With sleeve bearings
1R = Front ball bearing, rear sleeve bearing
2R = Front and rear ball bearings
 82 Magnet type / Commutation size & type
11, 18, 21, 28, 48, 58 = Alnico / Precious metal
12 = Alnico / Graphite-Copper
61, 78, 88, 98 = NdFeB / Precious Metal
82, 83 = NdFeB / Graphite-Copper
 426E Coil type
 50 Execution code