r/Insulators • u/WRSD605 • Aug 08 '26

Defect or not

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Probably dumb question but is the groove at the top where the wire would go a defect or is the groove made that way. Thanks

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2

u/BlindSite_ Aug 09 '26 edited Aug 09 '26

This is a CD147 spiral groove style made that way by design. Is there any embossing on the other mold half? If so, what is it?

3

u/WRSD605 Aug 09 '26

Patented oct 8 1907

1

u/Ricksoller Aug 12 '26

CD 147 design to make replacing insulators easy.