Slip Ring Brushes

BRUSH CONTACT MATERIAL

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The following chart gives some basic information on the most common brush contact materials.

Grade Number	Composition	Recommended Surface Speed	Carrying Capacity
FAG 180	80% Silver 20% Graphite	Up to 3500 feet per minute	250 amps per square inch
FAG 180A	80% Silver 20% Graphite plus MoS2	Up to 3500 feet per minute	250 amps per square inch
FAG 150	50% Silver 50% Graphite	Up to 6000 feet per minute	100 amps per square inch
FAG 150A	50% Silver 50% Graphite plus MoS2	Up to 6000 feet per minute	100 amps per square inch
FAG 193	93% Silver 7% Graphite	Up to 250 feet per minute	300 amps per square inch

Fabricast grade FAG180 is the low noise level grade used for all standard slip rings. In general, a noise level of approximately 1 microvolt for each milliampere of current flow can be accomplished depending on the speed of the unit and quantity of brushes per ring.

Fabricast grade FAG150 is the highest surface speed grade: however, noise levels are slightly higher than FAG180. Brush life is approximately twice that of FAG180. It is recommended when brush life is critical and/or surface speed is high. Low noise can be achieved with multiple contacts per ring.

Fabricast grade FAG193 has highest current carrying capacity; however, it is limited to a surface speed of 250 ft. per minute.

Fabricast grades FAG180A and FAG150A contain molybdenum disulfide in addition to silver and graphite. This additive is required for operation in altitude, vacuum, and inert environments. Other characteristics remain the same.

PLUNGER TYPE BRUSHES Download printable PDF of this page
Plunger type brushes consist of a brass holder with cap, a copper or BeCu buss assembly, and a spring loaded silver graphite plunger brush. Both holder and buss are tin plated. Brush holders are most commonly press fit into a dielectric brush block or soldered/brazed to a buss which is then bolted to the brush block.

2.5 AMP CAPACITY • 3/32” SQUARE

4 AMP CAPACITY • 1/8” SQUARE 10 AMP CAPACITY • 3/16” X 1/4” RECTANGULAR

25 AMP CAPACITY • 1/4” X 1/2” RECTANGULAR 50 AMP CAPACITY • TWO EACH 1/4” X 1/2” RECTANGULAR

The following chart shows the different plunger brush part numbers for specific brush sizes and brush grades. Download printable PDF of this page

Plunger Brush Part Number Chart
Brush Size	Brush Grade
	FAG 180	FAG 150	FAG 180A	FAG 150A	FAG 193
3/32″ Square	1072-1	1072-5	1072-11	1072-10	1072-14
1/8″ Square	1072-2	1072-6	1072-13	1072-12	1072-15
3/16″ x 1/4″	1913-1	1913-2	1913-3	1913-4	1913-5
*1/4″ x 1/2″	1092003	1092003-31	1092003-29	1092003-27	1092003-25
**1/4″ x 1/2″	1991-1	1991-2	1991-3	1991-4	1991-5

* For use with brush holder P/N 1092006
** For use with brush holder P/N 1092012

For complete information on the different plunger brushes and holders available please download relevant catalog pages or request a Fabricast catalog by phone, Email, or by completing the Request For More Information Form.

LEAF TYPE BRUSHES Download printable PDF of this page

Leaf springs for Fabricast leaf type brushes are made of beryllium copper alloy #25. The leaf springs are heat treated and tin plated. The silver graphite brush contacts are soldered onto the leaf springs.

2 AMP CAPACITY • SINGLE BRUSH
BRUSH .040 WIDE • BRUSH MATERIAL – FAG 180 (80% AG – 20% C) • LEAF MATERIAL – BECU

5 AMP CAPACITY • DOUBLE BRUSH
BRUSH .040 WIDE • BRUSH MATERIAL – FAG 180 (80% AG – 20% C) • LEAF MATERIAL – BECU

5 AMP CAPACITY • SINGLE BRUSH
BRUSH .090 WIDE • BRUSH MATERIAL – FAG 180 (80% AG – 20% C) • LEAF MATERIAL – BECU

OPTION: Opposite hand assemblies available. Optional brush location shown in phantom.

5 AMP CAPACITY • SINGLE BRUSH
BRUSH .090 WIDE • BRUSH MATERIAL – FAG 180
(80% AG – 20% C) • LEAF MATERIAL – BECU[/fusion_builder_column_inner]