| General Unipart Insulators |
Unipart insulators are by far the largest category of porcelain. They include any single piece pin type porcelain insulator. This also includes glaze-welded pieces which have separate shells that are fused together with extra glaze.
You may notice a large number of insulators attributed to Pittsburg. Pittsburg High Voltage produced more styles of porcelain insulators than any other company. They copied many glass styles (U-177 = CD 152; U-179 = CD 162.5; U-410 = CD 251, and U-395 = CD 257, just to name a few), as well as having a wide range of colors. Pittsburg started business in 1908 an in 1922 became part of Westinghouse. Few Pittsburg insulators are marked, although some have a characteristic date stamp like (JUN 17 1915) OR (NOV 30 ANS'D), but there are a number of characteristics that help identification for an experienced collector.
These photos include both rare early styles and colored pieces. The manufacturer (if known) and any markings are provided.