Cunren Carbon Brush

Cunren is a full industry chain carbon brush manufacturer, including materials and finished products. 

Introduction

Shanghai Pro-wind/Cunren Carbon Co., Ltd is a manufacturing enterprise established in 1980 and becoming the largest carbon brush products manufacturer with an annual manufacturing capacity of 140 tons of electro graphite block and 12 million of carbon brushes with accredited quality.
Our Nature graphite, electro graphite, copper graphite material carbon brush products have covered most of the applications in different industries, and acquired market share from many famous carbon group’s product. 
Positioned the upstream in the whole industrial chain, we’ve got a really big list of the customers both domestically and globally, we are prepared to work with you and assist you in new project with our engineering know-how. 
Cunren Carbon brush

Classes of Carbon Brushes Of Supply

Nature-Graphite-carbon-brush

Natural graphite

The natural graphite is main raw material of this class of carbon brushes. And pitch and resin are used as binders, which are baked together with graphite at about 1000℃.
This class of brushes are provided with better lubricating and current-
collecting performance. The natural graphite brushes are respectively used with the slip rings of small and medium size DC motor and high speed turbo-generators under steady applications.

Electro-graphite carbon brush

Electro graphite

This class of carbon brushes consist of various kinds of carbon powders such as carbon black, coke, graphite and so on. They must undergo high temperature treatment at about 2500°C to make all
kinds of carbonic material convert to a micro—crystalline form of artificial
graphite. Hence E 1 is electro graphite base, E 2 with coke base and E3 with carbon black base.
This class of brushes have excellent characteristic of commutating and self-
lubricating, widely applied to all kinds of AC and DC motors with the advantage of long service life and less wear against the commutators.

Electro-graphite carbon brush

Metal graphite

This main raw material used for this class of carbon brushes are electrolytic copper powder and graphite. According to
the needs of users, powders of silver, lead and other metals can also be employed.

This class of brushes applicable to low voltage electrical machines with heavy load and ordinary requirements of
commutation. 

Generally, the peripheral speed should not exceed 30 m/s.

Specifications of Carbon Brush Materials

Electro Graphite Carbon Brush Grade

Grade

Resistivity
(Ω.m)

Rockwell
hardness
(HR10/)

Contact
Voltage
Drop
(V)

Coef of
Friction

Current
density

Max Surface Speed

Pressure
in using
(kPa)

Application

E17

7.8-18.2

103(196)

2.7

0.25

12

70

14.7-19.6

Slip rings of the high speed turbo-generators and DC 

machines of small and medium size

E21

21-35

82(980)

2.4

0.25

10

40

19.6-39.2

Carbon brushes for generators on automobile and traction motors with
mechanical vibration

E25

10.5-19.5

82(980)

2.5

0.25

12

45

19.6-24.5

Exciters of turbo generators and DC machines with shock load

E30

28-52

68(980)

2.6

0.25

10

40

19.6-39.2

120-44ov DC machines automobile generators and traction motors

E33

40-74

83(980)

2.8

0.25

12

50

19.6-39.2

Carbon brushes for traction motors and main generators for locomotives high speed excites for turbo-generators, rolling stock
motors and main generators, AC commutator motors and other DC motors with some difficulties of
commutation.

E33N

41-75

83(980)

2.8

0.2

12

60

19.6-39.2

Same with grade E33

E33F

40-74

90(980)

2.7

0.2

12

50

19.6-39.2

Same with grade E33

E36N

42-78

99(588)

2.9

0.25

12

50

19.6-39.2

Same with grade E33

Metal Graphite Carbon Brush Grades

Grade

Resistivity
(Ω.m)

Rockwell
hardness
(HR10/)

Contact
Voltage
Drop
(V)

Coef of
Friction

Current
density

Max Surface Speed

Pressure
in using
(kPa)

Application

CG94

94% Cu

0.03-0.09

59-105

(392)

<0.4

0.25

20

20

17.67-22.5

Contacts

CG82

82% Cu

0.045-0.135

30-92

(392)

0.18-0.42

0.2

20

20

17.67-22.5

Low voltage AC  Commutator machines with slip rings

CG72

72% Cu

0.24-0.96

37-105

(588)

0.61-1.6

<0.2

15

20

19.6-24.5

Carbon brushes for DC machines up to
4oV, automobile starters and exciting slip rings of asynchronous machines

CG60

60% Cu

1.0-4.0

66-113

(588)

0.78-1.82

0.25

15

35

19.6-24.5

Carbon brushes for Automobile starters and exciting slip rings of synchronous machines

CG50

50% Cu

1.4-5.6

63-103

(588)

0.83-2.28

0.25

15

25

14.7-19.6

DC generators up to 60V and DC welding machine

CG25

25% Cu

4.4-13.2

30-90

(588)

1.17-2.43

0.25

12

20

14.7-19.6

Carbon brushes for DC machines up to 80V,small traction motors
and slip rings of
asynchronous motors

SG50

50% Ag

2.4

89(588)

1.2

0.3

15

20

14.7-19.6

DC measure speed
electrical machines, AC and DC miniature electrical machines

SG70

70% Ag

0.41

84(588)

0.73

0.28

15

20

14.7-19.6

Carbon brushes for DC measure speed
electrical machines, AC and DC miniature electrical machines

SG90

90% Ag

0.07

82(588)

0.2

0.25

20

15

14.7-19.6

DC measure speed
electrical machines, AC and DC miniature electrical machines

Natural Graphite Carbon Brush Grade

Grade

Resistivity
(Ω.m)

Rockwell
hardness
(HR10/)

Contact
Voltage
Drop
(V)

Coef of
Friction

Current
density

Max Surface Speed

Pressure
in using
(kPa)

Application

NG634

17-25

46-77

(196)

<2.5

per brush

0.27

10

70

14.7-19.6

Large turbo generators with slip rings

Resin-Bonded Carbon Brush Grade

Grade

Resistivity
(Ω.m)

Rockwell
hardness
(HR10/)

Contact
Voltage
Drop
(V)

Coef of
Friction

Current
density

Max Surface Speed

Pressure
in using
(kPa)

Application

R015

329-611

76-120

(196)

3.36-6.24

0.2

8

30

19.6-314.2

Power tools carbon brushes

R211

147-273

56-84

(588)

3.6-5.4

0.2

8

35

24.5-34.5

DC or AC commutator

machines