North American Spool Insulators

Spool or knob insulators typically have a non-threaded hole in the center for mounting and a wire groove around the outside. These insulators are used for dead ending a communication or power line and are often found mounted on racks on the sides of buildings where the wires enter the building. They are also used for wire transposition where two or four spools are mounted such that the wires can tie off and cross. Glass spool and knob insulators have been assigned CD 1049-1110. See the following reference for more information:

Note: Click on each insulator for larger pictures and more information!

Spool or knob insulators have been assigned CD 1049-1110

CD 1049