CuW Contact Finger

Contact fingers are the spring-loaded contact elements used in plug-in assemblies, the moving side of a draw-out VCB, the touch-and-break contact in disconnector assemblies, and similar applications. The CuW tip handles arc duty during making and breaking; the rest of the finger handles the continuous current and the spring action.

We supply two forms: integrated CuW fingers (full CuW length, simpler design but heavier) and CuW-tipped fingers brazed to copper or bronze bodies (lower cost, lighter, more common). Tip grades available in CuW70 / 75 / 80; the body material follows your design.

Specifications

Property	Value
Tip Material Grade	CuW70 / CuW75 / CuW80
Body Material	Copper or bronze (per drawing); or full CuW
Form	Spring-action finger with CuW tip
Finger Length	Per drawing
Tip Length	Per drawing
Cross Section	Per drawing
Tolerance	Per drawing
Surface Treatment	Tip as machined; body silver plated by default
Working Voltage	Common MV ratings: 12 / 24 / 40.5 kV
Working Current	Per-finger rating depends on design; assembly current is N × finger

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

Applications

• Draw-out VCB plug-in contact assemblies (12 / 24 / 40.5 kV)
• Disconnector and earthing switch contact fingers
• Make-and-break contact elements in MV switchgear cassettes
• Replacement fingers for installed draw-out switchgear fleets

Technical Notes

The CuW tip on a contact finger is the part doing arc work; the rest of the finger is a mechanical and conductive structure. Tip length matters: a longer CuW tip lasts longer through repeated operations but adds cost and weight. Most production designs keep the tip just long enough to outlast the assembly's specified electrical life.

For a brazed assembly (CuW tip + copper body), the braze joint is the weak point if not done right. We braze CuW to copper in-house with copper-silver fillers under controlled atmosphere; joint shear strength is consistent with industry practice for the material pair.

If your design has multiple fingers in parallel (a typical plug-in contact uses 4–12 fingers), the per-finger current rating multiplied by the finger count gives the assembly rating. Each finger should be specified to handle its share, with margin for current sharing imbalance.

Sourcing & OEM

Custom fingers from drawing are routine, whether integrated CuW or CuW-tipped. MOQ, lead time, and plating options vary by specification; contact us with your drawing for a project-specific quote.