Bronze Bushing for MV Switchgear

Bronze bushings support moving shafts and provide bearing surfaces in MV switchgear operating mechanisms, the shaft that drives a moving contact, the pivot points in a disconnector linkage, the support points where electrical isolation matters as much as mechanical wear. Aluminum bronze (typically C95400) handles these duties better than pure copper: harder, more wear-resistant, more corrosion-resistant in installed environments.

We supply bronze bushings as individual machined components or as complete bushing-and-shaft sub-assemblies. Custom geometries from drawing are routine.

Specifications

Property	Value
Alloy	Aluminum bronze C95400 (default); C95500 / C95800 on request
Form	Bushing (cylindrical with optional flange, to drawing)
Inside Diameter	Per drawing
Outside Diameter	Per drawing
Length	Per drawing
Tolerance	Per drawing, typical machining tolerance for the alloy
Conductivity	10–15% IACS (C95400), per ASTM B505 typical
Density	7.45 g/cm³ (C95400 typical)
Hardness (HB)	150–200 (C95400 typical, depending on temper)
Surface Treatment	As machined; silver plating optional for contact surfaces
Working Voltage	Common MV ratings: 12 / 24 / 40.5 kV

Exact certified properties for your lot are available with material documentation on request.

Applications

• Bushing for moving contact shaft in MV switchgear (12 / 24 / 40.5 kV)
• Bearing support for disconnector linkages and operating mechanisms
• Isolation bushings in compound switchgear assemblies
• Replacement bushings for installed MV switchgear refurbishment

Technical Notes

The bushing's job is two things at once: support mechanical motion (slide, rotate, pivot) and provide either electrical isolation or controlled conductivity, depending on the design. Aluminum bronze handles both. The alloy is hard enough to resist galling against steel or brass shafts, conductive enough to handle low-frequency contact currents, and corrosion-resistant enough to survive decades in installed switchgear environments.

For sliding interfaces, internal lubrication is sometimes added (oil grooves, graphite-filled bores). For high-cycle applications, silver plating on the bushing interior reduces contact resistance at the rotating interface. Both are routine to add per drawing.

Bushing wall thickness and tolerance affect both the mechanical fit and the bushing's ability to handle thermal expansion. For tight-tolerance fits at varying ambient temperatures, specify the expected operating range.

Sourcing & OEM

Custom bronze bushings to your drawing are routine. Specify the alloy, dimensions, surface treatment, and any internal features (grooves, plating); contact us with the drawing or sample for a project-specific quote.