Item Type: CSA Insulator
Values: Check below on Ebay for approximate prices
Sizes and ID#s: CSA (CD 128)
I was unsure which category these Pyrex Insulators should go in - so for now it’s in Ovenware - Miscellaneous. These are very interesting insulators made out of glass that were used in conjunction with wires and circuits, usually on poletops. Various companies made them - Corning made a bunch of different ones out of Pyrex. There are a huge amount of Insulator collectors. I personally find insulators very interesting, but I know little about them currently. I have a few other ones, but none of them say Pyrex.
From the Insulators.com website I was able to deduce that this particular model of Pyrex insulator is fairly common. It is marked on one side as “Pyrex BF TM REG U.S. Pat. Off.” which is how I knew right away it was made out of Pyrex.
The other side is marked “CSA Made In U.S.A. 41″. From the insulators.com site, it says that CSA translates to a CD Number of 128 (The CD number stands for “Consolidated Design which is a number assigned to specific shapes of these insulators, no matter who the manufacturer was.) The C stands for “Carrier circuit application” and the S stands for “Steel” which is the type of pin it was put on. The A doesn’t stand for anything apparently.
I don’t really know when the years this was manufactured. I think I have seen one very similar to this where the bottom “skirt” was actually threaded instead of smooth.
Selected Pyrex items: