Specialty Electrical Porcelain
(Non-Standard Porcelain Electrical Insulators)
Other Photos - These are photos that show insulators in service.
Catalogs - under construction
Porcelain manufacturers produced a lot of different styles other than the Standard Porcelain styles. These insulators were called "specialty porcelain" and it was a large part of business for many companies. Also, several customers, such as telephone companies, wanted their names on the items. A great variety is shown on these pages, but it is just a small sampling of all the various specialty items. In later years, making specialty porcelain became too costly, so customers were forced to purchase standard styles, which were much cheaper to make in mass quantities.
The following table shows 57 different specialty porcelain insulators in my collection. Cataloging specialty porcelain does not follow any sort of categorizing. The cataloging numbers us "SP" for specialty porcelain with the number following simply a reference number for the particular style. In order to see photos of each style, click on the link in the table for a specific insulator, or browse the pages of photos: Photos of Specialty Porcelain.
SP = Specialty Porcelain
emb: embossed
r-e: recess-embossed
u-g: under-glaze ink
/ : marking on opposite side
// : marking on bottom or opposite side
| No. | MARKING | Marking Type | Color | Company | Notes |
|---|---|---|---|---|---|
| SP1-01
|
N. E. T. & T. CO. / U. S. A. | r-e / emb | white | New England Telephone & Telegraph Co. | |
| SP1-02
|
N E T & T | r-e | white | New England Telephone & Telegraph Co. | |
| SP1-03
|
.N. E. T. & T. CO. | r-e | white | New England Telephone & Telegraph Co. | |
| SP2-01
|
S. M. T. CO. | emb | white | Southern Massachusetts Telephone Co. | |
| SP2-02
|
N E T & T CO | emb | white | New England Telephone & Telegraph Co. | |
| SP2-03 |
N. E. T. & T. CO. | emb | white | New England Telephone & Telegraph Co. | |
| SP3-01
|
S. M. T. CO. | r-e | white | Southern Massachusetts Telephone Co. | |
| SP3-02
|
N E T & T CO | r-e | white | New England Telephone & Telegraph Co. | |
| SP3-03
|
N. E. T. & T. CO. / .T | r-e / emb | white | New England Telephone & Telegraph Co. | |
| SP3-04
|
C. O. P. | emb | white | Carey Ohio Porcelain Co. | |
| SP3-05
|
KNOX / 6061 | r-e | white | Knox Porcelain Corp. | |
| SP3-06 |
P. P. / U.S.A. / 6061 | r-e | white | Porcelain Products Inc. | |
| SP3-07 |
N-N | white | |||
| SP3-08
|
N. E. T. & T. CO. | emb | white | New England Telephone & Telegraph Co. | |
| SP3-09
|
N E T & T CO | emb | white | New England Telephone & Telegraph Co. | |
| SP3-10
|
P. P. INC. / U.S.A. / 6061 | emb | white | Porcelain Products Inc. | |
| SP4-01
|
F | emb | white | ||
| SP4-02
|
N-N | white | |||
| SP4-03
|
PATENTED | emb | white | patent 948,321 | |
| SP5-01 |
N-N | white | |||
| SP6-01 |
N-N (Thomas) | brown | |||
| SP7-01 |
N-N (Findlay) | white | |||
| SP8-01
|
N. E. T. & T. CO. | r-e | white | New England Telephone & Telegraph Co. | |
| SP8-02
|
N. E. T. & T. CO. | r-e | white | New England Telephone & Telegraph Co. | |
| SP8-03
|
N. E. T. & T. CO. | r-e | white | New England Telephone & Telegraph Co. | |
| SP8-04
|
N. E. T. & T. CO. / T | r-e | white | New England Telephone & Telegraph Co. | |
| SP8-05
|
KNOX / 7139 | r-e | white | ||
| SP8-06 |
N-N | white | |||
| SP9-01
|
HALL / G | emb | white | ||
| SP9-02
|
A. P. Co. | emb | white | ||
| SP10-01
|
S M T CO | r-e | white | Southern Massachusetts Telephone Co. | |
| SP10-02
|
N E T & T CO | r-e | white | New England Telephone & Telegraph Co. | |
| SP10-03
|
N E T & T CO | r-e | white | New England Telephone & Telegraph Co. | |
| SP10-04 |
U (in circle) | r-e | white | ||
| SP10-05 |
T (underneath) | r-e | white | ||
| SP10-06 |
N-N | white | |||
| SP10-07 |
N-N | white | |||
| SP10-08 |
KNOX / 6062 | r-e | white | Knox Porcelain Corp. | |
| SP11-01 |
N-N | white | |||
| SP11-02 |
N-N | brown | |||
| SP12-01 |
PATD. JAN. 16, 1917 | r-e | white | patent 1,213,011 | |
| SP13-01 |
N-N | white | 2" x 2-1/8" | ||
|
|
|
||||
| SP14-01 | NO. 8 P&S / PAT. JUNE 14 92 | r-e | white | Bain break knob; patent 476,813 | |
| SP14-02 | F. E. P. CO. / 1922 | emb | brown | Bain break knob | |
| SP14-03 | P&S / PAT / 14 ?? | r-e | white | Bain break knob; patent 476,813 | |
| SP14-04 | P&S NO ? / PAT.D | emb | white | Bain break knob; patent 476,813 | |
| SP14-05 | P & S / PAT.D | emb | white | Bain break knob; patent 476,813 | |
| SP15-01 |
N-N | white | 1-3/8" x 2" | ||
| SP16-01 |
B F / R C | emb | white | ||
| SP16-02 |
KRETZER BRAND | emb | white | ||
| SP16-03 |
NO 32 (underneath) | emb | white | ||
| SP16-04 |
N-N | white | |||
| SP16-05 |
KRETZER BRAND | emb | white | ||
| SP17-01 |
N-N | white | Gamewell Fire Alarm Telegraph Co. | Jimmy Burns referenced Gerald Brown's book: It was used as a support for glass rods upon which batteries were placed. The batteries were electrical backup for Gamewell fire alarms. Patent dated Sept. 4, 1923 (1,466,674) was associated with the battery. | |
| SP17-02 |
N-N | white | |||
| SP18-01 |
KNOX / 7050 | r-e | white | ||
| SP18-02 |
N-N | white | |||
| SP18-03 |
WISP / NO. 3 | r-e | white | ||
| SP19-01 |
SACKETT / PATD NOV 10 08 | emb | white | patent 903,692; mine insulator | |
| SP20-01 |
UNIVERSAL / 1001 // PATENTED / APR 12 1910 | r-e | brown | patent 954,596; commonly called the baby Universal fire plug | |
| SP20-02 |
1002 // Triangle M | r-e | brown | patent 954,596; medium size Universal fire plug | |
| SP20-03 |
PATENTED / APR 12 1910 // Triangle M | r-e | brown | patent 954,596; large size Universal fire plug |