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Porcelain Threadless Pintype

Insulators from the United States

Porcelain pintype threadless insulators date from the 1850's through the early 1870's.  These insulators saw significantly lower production than their glass counterparts but still can be found in  a wide variety of styles!  These insulators are also identified in the hobby by U (Unipart) numbers.  The following reference provides historical information as well as U number designations.  Thanks to Doug MacGillvary & Carol McDougald for most of these photographs.

Porcelain Insulators Guide Book For Collectors (Unipart Pin Types)

U-970

U-971

U-979

U-980

U-981

U-982

U-983

U-985

U-986

U-987

U-988

U-989

U-990


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