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Ball-strain insulator, ca. 1920

Ball-strain insulator, ca. 1920

Item 74836 zoom send e-card Share this on Facebook Share this on Twitter

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Description

Nicknamed the "Johnny Ball," this insulator is made of a composite material containing asphalt, shellac and asbestos.

Strain insulators are used in the guy wires supporting utility poles or radio antennas to break the electrical path and prevent short circuits or grounding.

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