U-436-535

(Cable top styles with a ridged skirt)
U-436
Manufacturer or Marking
No Name (USA)

NOTE: In 2008 and older reference books, there was a U-436C listed. Listing are now moved to U-436. Old U-436, U-436A and U-436B are now removed.
U-436
Size: 57mm X 73mm (2 ¼ x 2 ⅞)
Example in Photo: No Name (USA)
Photo Credit: Ken Willick
To directly link to this image copy and paste below URL:
U-437
Manufacturer or Marking
No Name (USA)
Locke (USA)
O-B (USA)
U-437
Size: 76mm X 85mm (3 x 3 ⅜)
Example in Photo: Locke (USA)
Photo Credit: Charles Robinson
To directly link to this image copy and paste below URL:
U-437A
Manufacturer or Marking
No Name (USA)
Westinghouse (USA)
U-437A
Size: 76mm X 88mm (3 x 3 ½)
Example in Photo: No Name (USA)
Photo Credit: Bill Rohde
To directly link to this image copy and paste below URL:
U-437B
Manufacturer or Marking
Locke (Fred Locke Attic Dig) (USA)

NOTE: In 2008 and older reference books, this was known as U-437C. The old listing for U-437B was deleted and this one moved in to its spot.
U-437B
Size: 63mm X 76mm (2 ½ x 3)
Example in Photo: Locke (Fred Locke Attic Dig) (USA)
Photo Credit: Ken Willick
To directly link to this image copy and paste below URL:
U-438
Manufacturer or Marking
No Name (USA)
No Name (Pittsburg) (USA)

NOTE: In 2008 and older reference books, there was a U-438A and U-438B listed. They are now merged with U-438
U-438
Size: 88mm X 88mm (3 ½ x 3 ½)
Example in Photo: No Name (USA)
Photo Credit: Fred Collier
To directly link to this image copy and paste below URL:
U-438A
Manufacturer or Marking
No Name (Pittsburg) (USA)

NOTE: In 2008 and older reference books, there was a U-438C listed. Listing are now part of U-438A.
U-438A
Size: 88mm X 85mm (3 ½ x 3 ⅜)
Example in Photo: No Name (USA)
Photo Credit: Matt Grayson
To directly link to this image copy and paste below URL:
U-440
Manufacturer or Marking
No Name (USA)
U-440
Size: 88mm X 79mm (3 ½ x 3 ⅛)
Example in Photo: No Name
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-441
Manufacturer or Marking
No Name (USA)
Fred Locke (USA)
U-441
Size: 82mm X 73mm (3 ¼ x 2 ⅞)
Example in Photo: Fred Locke (USA)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-441A
Manufacturer or Marking
No Name (USA)
No Name (Lima) (USA)
Fred Locke (USA)

NOTE: In 2008 and older reference books, there was a U-450 listed. Listing are now moved to U-441A.
Size: 93mm X 73mm (3 x 2 )
Variations: Click on the thumbnail above to see style variations
Variations: Tap on the thumbnail above to see style variations
To directly link to this image copy and paste below URL:
U-441B
Manufacturer or Marking
Fred Locke (USA)
No Name (USA)
U-441B
Size: 92mm X 73mm (3 x 2 )
Example in Photo: Fred Locke (USA)
Photo Credit: Elton Gish
To directly link to this image copy and paste below URL:
U-441C
Manufacturer or Marking
No Name (New Lexington, flat inner skirt) (USA)
No Name (Trenton) (USA)
Size: 95mm X 79mm (3 ¾ x 3 ):
Variations: Click on the thumbnail above to see style variations
Variations: Tap on the thumbnail above to see style variations
To directly link to this image copy and paste below URL:
U-441D
Manufacturer or Marking
O-B (USA)
U-441D
Size: 95mm X 76mm (3 ¾ x 3)
Example in Photo: O-B (USA)
Photo Credit: Michael Green
To directly link to this image copy and paste below URL:
U-442
Manufacturer or Marking
No Name (USA)
U-442
Size: 85mm X 73mm (3 x 2 ⅞)
Example in Photo: No Name (USA)
Photo Credit: Fred Collier
To directly link to this image copy and paste below URL:
U-443
Manufacturer or Marking
No Name (USA)
MACOMB (USA)
O-B (USA)
Triangle M (USA)
U-443
Size: 95mm X 73mm (3 ¾ x 2 ⅞)
Example in Photo: MACOMB (USA)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-444
Manufacturer or Marking
No Name (USA)
Triangle M (USA)
U-444
Size: 101mm X 85mm (4 x 3 ⅜)
Example in Photo: No Name (USA)
Photo Credit: Charles Robinson
To directly link to this image copy and paste below URL:
U-446
Manufacturer or Marking
No Name (USA)
No Name (Pittsburg) (USA)
No Name (Thomas, Dry Process) (USA)
IEP (USA)
U-446
Size: 88mm X 73mm (3 ½ x 2 ⅞)
Example in Photo: No Name (USA)
Photo Credit: Elton Gish
To directly link to this image copy and paste below URL:
U-446A
Manufacturer or Marking
No Name (Akron H-P, Dry Process) (USA)
No Name (Thomas, Dry Process) (USA)
U-446A
Size: 95mm X 76mm (3 ¾ x 3)
Example in Photo: No Name (Thomas, Dry Process) (USA)
Photo Credit: Elton Gish
To directly link to this image copy and paste below URL:
U-447
Manufacturer or Marking
No Name (USA)
No Name (Westinghouse) (USA)
Locke (USA)
O-B (USA)
Pinco (USA)
Westinghouse (USA)
U-447
Size: 95mm X 76mm (3 ¾ x 3)
Example in Photo: O-B (USA)
Photo Credit: Elton Gish
To directly link to this image copy and paste below URL:
U-447A
Manufacturer or Marking
Pinco (USA)
U-447A
Size: 95mm X 76mm (3 ¾ x 3)
Example in Photo: Pinco (USA)
Photo Credit: Elton Gish
To directly link to this image copy and paste below URL:
U-448
Manufacturer or Marking
No Name (USA)
No Name (Triangle M) (USA)
Locke (USA)
O-B (USA)
Pinco (USA)
Triangle M (USA)

NOTE: In 2008 and older reference books, there was a U-447B and U-447C listed. Listing are now part of U-448.
U-448
Size: 98mm X 82mm (3 x 3 ¼)
Example in Photo: O-B (USA)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-449
Manufacturer or Marking
No Name (USA)
U-449
Size: 101mm X 82mm (4 x 4 3 ¼)
Example in Photo: No Name (USA)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-451
Manufacturer or Marking
No Name (Dry Process, Mold Lines) (USA)
No Name (Thomas) (USA)
No Name (USA)
O-B (USA)
Pinco (USA)
R (On side) (USA)
U-451
Size: 98mm X 76mm (3 x 3)
Example in Photo: No Name (Thomas) (USA)
Photo Credit: Elton Gish
To directly link to this image copy and paste below URL:
U-451A
Manufacturer or Marking
No Name (Lima) (USA)
No Name (USA)
No Name (Dry Process) (USA)
U-451A
Size: 98mm X 76mm (3 x 3)
Example in Photo: No Name (Dry Process) (USA)
Photo Credit: Elton Gish
To directly link to this image copy and paste below URL:
U-452
Manufacturer or Marking
No Name (USA)
No Name (Triangle M) (USA)
Triangle M (USA)

NOTE: In 2008 and older reference books, there was a U-452A listed. Listing are now part of U-452.
Size: 101mm X 85mm (4 x 3 )
Variations: Click on the thumbnail above to see style variations
Variations: Tap on the thumbnail above to see style variations
To directly link to this image copy and paste below URL:
U-457
Manufacturer or Marking
KNOX (USA)
PP (USA)
U-457
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Example in Photo: KNOX (USA)
Photo Credit: Dave Kingston
To directly link to this image copy and paste below URL:
U-459
Manufacturer or Marking
No Name (USA)
Lapp (USA)
U-459
Size: 98mm X 76mm (3 x 3)
Example in Photo: No Name (USA)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-460
Manufacturer or Marking
No Name (Cook) (USA)
COOK (USA)
Lapp (USA)
U-460
Size: 95mm X 79mm (3 ¾ x 3 )
Example in Photo: COOK (USA)
Photo Credit: Bill Vincent
To directly link to this image copy and paste below URL:
U-460A
Manufacturer or Marking
No Name (USA)
Knox (USA)
Locke (USA)
Victor Insulators. Inc. (USA)
U-460A
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Example in Photo: Knox (USA)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-462
Manufacturer or Marking
No Name (USA)
Knox (USA)
Lapp (USA)
Locke (USA)
U-462
Size: 95mm X 76mm (3 ¾ x 3)
Example in Photo: Knox (USA)
Photo Credit: Fred Collier
To directly link to this image copy and paste below URL:
U-463
Manufacturer or Marking
No Name (USA)
Pinco (USA)
THOMAS (USA)
U-463
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Example in Photo: THOMAS (USA)
Photo Credit: Kyle Donaldson
To directly link to this image copy and paste below URL:
U-464
Manufacturer or Marking
No Name (USA)
Franklin Porcelain (USA)
Hartford Faience (A107) (USA)
Knox (USA)
Victor Ins. Inc. (USA)

NOTE: In 2008 and older reference books, there was a U-464A listed. All listings are now part of U-464
U-464
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Example in Photo: Hartford Faience (A107) (USA)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-465
Manufacturer or Marking
KNOX (USA)
U-465
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Example in Photo: KNOX (USA)
Photo Credit: Fred Collier
To directly link to this image copy and paste below URL:
U-465A
Manufacturer or Marking
KNOX (USA)
U-465A
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Example in Photo: KNOX (USA)
Photo Credit: Unknown
To directly link to this image copy and paste below URL:
U-466
Manufacturer or Marking
No Name (USA)
Chance (USA)
IEP (USA)
Illinois (USA)
Line Material (USA)
Locke (USA)
U-466
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Example in Photo: IEP (USA)
Photo Credit: Fred Collier
To directly link to this image copy and paste below URL:
U-467
Manufacturer or Marking
No Name (USA)
Illinois (USA)
Locke (USA)
Triangle M (USA)
Victor Ins. Inc. (USA)
U-467
Size: 101mm X 92mm (4 x 3 )
Example in Photo: Illinois (USA)
Photo Credit: Charles Robinson
To directly link to this image copy and paste below URL:
U-470
Manufacturer or Marking
No Name (USA)
U-470
Size: 95mm X 79mm (3 ¾ x 3 ⅛)
Example in Photo: No Name (USA)
Photo Credit: Fred Collier
To directly link to this image copy and paste below URL:
U-472
Manufacturer or Marking
No Name (USA)
No Name (Westinghouse) (USA)
COOK (USA)
Findlay (USA)
G.P.Co. (USA)
Knox (USA)
P.P. Inc. (USA)
Triangle M (USA)
Westinghouse (USA)

NOTE: In 2008 and older reference books, there was a U-471 (G.P.Co), It is now part of the listing for U-472
Size: 98mm X 79mm (3 x 3 )
Variations: Click on the thumbnail above to see style variations
Variations: Tap on the thumbnail above to see style variations
To directly link to this image copy and paste below URL:
U-473
Manufacturer or Marking
No Name (USA)
Locke (USA)
Pinco (USA)
Victor Ins. Inc. (USA)
U-473
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Example in Photo: No Name (USA)
Photo Credit: Elton Gish
To directly link to this image copy and paste below URL:
U-473A
Manufacturer or Marking
No Name (USA)
Chance (USA)
J-D (USA)
Locke (2) (USA)
P.P. Inc. (USA)
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Variations: Click on the thumbnail above to see style variations
Variations: Tap on the thumbnail above to see style variations
To directly link to this image copy and paste below URL:
U-474
Manufacturer or Marking
No Name (USA)
Chance (USA)
Findlay (USA)
G.P. Co. (USA)
Locke (USA)
N.E.P. (USA)
Pinco (USA)
P.P. Inc. (USA)
THOMAS (USA)
Victor Insulators. Inc. (USA)
Westinghouse (USA)
U-474
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Example in Photo: Findlay (USA)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-475
Manufacturer or Marking
No Name (USA)
No Name (Westinghouse) (USA)
Illinois (USA)
Locke (USA)
P.P. Inc. (USA)
Victor Ins. Inc. (USA)
Westinghouse (USA)
U-475
Size: 101mm X 85mm (4 x 3 ⅜)
Example in Photo: No Name (Westinghouse) (USA)
Photo Credit: Mid Norris
To directly link to this image copy and paste below URL:
U-476
Manufacturer or Marking
No Name (USA)
Chance (USA)
Knox (USA)
P.P. Inc. (USA)
U-476
Size: 104mm X 79mm (4 x 3 ⅛)
Example in Photo: No Name (USA)
Photo Credit: Fred Collier
To directly link to this image copy and paste below URL:
U-480
Manufacturer or Marking
No Name (USA)
No Name (Lapp) USA)
Lapp (USA)
Size: 98mm X 73mm (3 x 2 )
Variations: Click on the thumbnail above to see style variations
Variations: Tap on the thumbnail above to see style variations
To directly link to this image copy and paste below URL:
U-481
Manufacturer or Marking
No Name (USA)
General Electric (USA)
Lapp (USA)
Locke (USA)
Pinco (USA)
U-481
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Example in Photo: Locke (USA)
Photo Credit: Greg Hale
To directly link to this image copy and paste below URL:
U-482
Manufacturer or Marking
No Name (USA)
KNOX (USA)
Pinco (USA)
U-482
Size: 95mm X 85mm (3 ¾ x 3 )
Example in Photo: Pinco (USA)
Photo Credit: Bill Ostrander
To directly link to this image copy and paste below URL:
U-483
Manufacturer or Marking
Fred Locke (USA)
U-483
Size: 95mm X 88mm (3 ¾ x 3 ½)
Example in Photo: Fred Locke (USA)
Photo Credit: Mike Spadafora
To directly link to this image copy and paste below URL:
U-484
Manufacturer or Marking
No Name (USA)
Pinco (USA)
Victor (USA)
U-484
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Example in Photo: No Name (USA)
Photo Credit: Ben Kirsten
To directly link to this image copy and paste below URL:
U-485
Manufacturer or Marking
No Name (USA)
Findlay (USA)
Locke (USA)
U-485
Size: 95mm X 85mm (3 ¾ x 3 )
Example in Photo: No Name (USA)
Photo Credit: James Lindsey
To directly link to this image copy and paste below URL:
U-486
Manufacturer or Marking
No Name (USA)
3 / 1964 (USA)
IEP (USA)
Line Material (USA)
Locke (USA)
McGraw Edison (USA)
P.P. Inc (USA)

NOTE: In 2008 and older reference books, there was a U-486A listed. It is now part of U-486
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Variations: Click on the thumbnail above to see style variations
Variations: Tap on the thumbnail above to see style variations
To directly link to this image copy and paste below URL:
U-487
Manufacturer or Marking
No Name (USA)
KNOX (USA)
IEP (USA)
Line Material (USA)
Locke (USA)
P.P. Inc. (USA)
U-487
Size: 95mm X 88mm (3 ¾ x 3 ½)
Example in Photo: P.P. Inc. (USA)
Photo Credit: Michele Kotlarsky
To directly link to this image copy and paste below URL:
U-488
Manufacturer or Marking
No Name (USA)
Chance (USA)
IEP (USA)
Lapp (USA)
Pinco (USA)
P.P. - KNOX (USA)
U-488
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Example in Photo: Lapp (USA)
Photo Credit: Charles Robinson
To directly link to this image copy and paste below URL:
U-488A
Manufacturer or Marking
No Name (USA)
U-488A
Size: 92mm X 82mm (3 x 3 ¼)
Example in Photo: No Name (USA)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-489
Manufacturer or Marking
ITE (USA)
LAPP (USA)
U-489
Size: 101mm X 92mm (4 x 3 )
Example in Photo: LAPP (USA)
Photo Credit: James Lindsey
To directly link to this image copy and paste below URL:
U-490
Manufacturer or Marking
O-B (USA)
PP-KNOX (USA)
U-490
Size: 114mm X 98mm (4 ½ x 3 )
Example in Photo: LAPP (USA)
Photo Credit: Robin Harrison
To directly link to this image copy and paste below URL:
U-493
Manufacturer or Marking
No Name (USA)
FP (Franklin Porcelain) (USA)
Knox (USA)

NOTE: In 2008 and older reference books, there was a U-492 listed. Listing are now part of U-493.
U-493
Size: 95mm X 95mm (3 ¾ x 3 ¾)
Example in Photo: FP (Franklin Porcelain) (USA)
Photo Credit: Matt Grayson
To directly link to this image copy and paste below URL:
U-493A
Manufacturer or Marking
Hartford Faience (USA)
U-493A
Size: 95mm X 101mm (3 ¾ x 4)
Example in Photo: Hartford Faience (USA)
Photo Credit: Steve Jones
To directly link to this image copy and paste below URL:
U-496
Manufacturer or Marking
Pinco (USA)
LOCKE (USA)

NOTE: In 2008 and older reference books, there was a U-496A Listing. It is not part of U-496
U-496
Size: 95mm X 88mm (3 ¾ x 3 ½)
Example in Photo: Locke (USA)
Photo Credit: James Lindsey
To directly link to this image copy and paste below URL:
U-497
Manufacturer or Marking
No Name (USA)
Pinco (USA)
U-497
Size: 95mm X 95mm (3 ¾ x 3 ¾)
Example in Photo: No Name (USA)
Photo Credit: Fred Collier
To directly link to this image copy and paste below URL:
U-497A
Manufacturer or Marking
No Name (USA)
U-497A
Size: 95mm X 101mm (3 ¾ x 4)
Example in Photo: No Name (USA)
Photo Credit: Robin Harrison
To directly link to this image copy and paste below URL:
U-497B
Manufacturer or Marking
No Name (USA)
PINCO (USA)
U-497B
Size: 88mm X 95mm (3 ½ x 3 ¾)
Example in Photo: PINCO (USA)
Photo Credit: Fred Collier
To directly link to this image copy and paste below URL:
U-498
Manufacturer or Marking
No Name (Pittsburg) (USA)
No Name (USA)
U-498
Size: 98mm X 92mm (3 x 3 ⅜)
Example in Photo: No Name (Pittsburg)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-499
Manufacturer or Marking
No Name (USA)
No Name (Thomas) (USA)
No Name (Lima) (USA)
U-499
Size: 98mm X 92mm (3 x 3 ⅜)
Example in Photo: No Name (Lima) (USA)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-499A
Manufacturer or Marking
No Name (USA)
O-B (USA)
U-499A
Size: 95mm X 92mm (3 ¾ x 3 )
Example in Photo: No Name (USA)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-500
Manufacturer or Marking
No Name (Pittsburg) (USA)
No Name (Lima) (USA)
No Name (USA)
O-B (USA)

NOTE: In 2008 and older reference books, this was known as U-500A. Old U-500 was merged with U-501 letting Old U-500A move to the newly available U-500 slot.
U-500
Size: 95mm X 85mm (3 ¾ x 3 ⅜)
Example in Photo: No Name (Lima) (USA)
Photo Credit: Ken Willick
To directly link to this image copy and paste below URL:
U-501
Manufacturer or Marking
No Name (USA)
No Name (Pittsburg) USA)
O-B (USA)

NOTE: In 2008 and older reference books, there was a U-500 listed. Listing are now part of U-501.
U-501
Size: 95mm X 88mm (3 ¾ x 3 ½)
Example in Photo: No Name (USA)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-502
Manufacturer or Marking
No Name (USA)
Knox (USA)
Westinghouse (USA)
U-502
Size: 88mm X 101mm (3 ½ x 4)
Example in Photo: No Name (USA)
Photo Credit: Matt Grayson
To directly link to this image copy and paste below URL:
U-503
Manufacturer or Marking
No Name (USA)
Chance (USA)
CP (Canada)
G.P.Co. (USA)
P.P. Inc. (USA)
Westinghouse (USA)

NOTE: CP (Canada) Units should also have a U-Number in the “Worldwide Porcelain Insulators Chart” range as U-1-999 are US only styles. No “Worldwide Porcelain Insulators” U-Number is yet available for this unit.
U-503
Size: 95mm X 95mm (3 ¾ x 3 ¾)
Example in Photo: P.P. Inc. (USA)
Photo Credit: Steve Coffman
To directly link to this image copy and paste below URL:
U-506
Manufacturer or Marking
No Name (USA)
Illinois (USA)
Knox (USA)
THOMAS (USA)

NOTE: In 2008 and older reference books, there was a U-505 listed. Listing are now part of U-506.
U-506
Size: 95mm X 92mm (3 ¾ x 3 ⅝)
Example in Photo: THOMAS (USA)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-511
Manufacturer or Marking
No Name (USA)
Hartford Faience (USA)
Illinois map (256) (USA)
Lapp (USA)
THOMAS (USA)

NOTE: in 2008 and older reference books, there was a U-510.It is now merged with U-511 as they are just variations of the same style.
U-511
Size: 92mm X 95mm (3 x 3 ¾)
Example in Photo: THOMAS (USA)
Photo Credit: Shaun Kotlarsky
To directly link to this image copy and paste below URL:
U-511A
Manufacturer or Marking
No Name (USA)
U-511A
Size: 101mm X 111mm (4 x 4 ⅜)
Example in Photo: No Name (USA)
Photo Credit: James Lindsey
To directly link to this image copy and paste below URL:
U-512
Manufacturer or Marking
No Name (USA)
Lapp (USA)
U-512
Size: 95mm X 88mm (3 ¾ x 3 ½)
Example in Photo: Lapp (USA)
Photo Credit: Charles Robinson
To directly link to this image copy and paste below URL:
U-513
Manufacturer or Marking
No Name (USA)
COOK (USA)
Lapp (USA)
Pinco (USA)
U-513
Size: 88mm X 95mm (3 ½ x 3 ¾)
Example in Photo: No Name (USA)
Photo Credit: Jim Frustieri
To directly link to this image copy and paste below URL:
U-514
Manufacturer or Marking
THOMAS (USA)
U-514
Size: 95mm X 114mm (3 ¾ x 4 ½)
Example in Photo: THOMAS (USA)
Photo Credit: Ben Kirsten
To directly link to this image copy and paste below URL:
U-515
Manufacturer or Marking
KNOX (USA)
U-515
Size: 92mm X 111mm (3 x 4 )
Example in Photo: KNOX (USA)
Photo Credit: Bill Ostrander
To directly link to this image copy and paste below URL:
U-515A
Manufacturer or Marking
KNOX (USA)
U-515A
Size: 92mm X 127mm (3 x 5)
Example in Photo: KNOX (USA)
Photo Credit: Elton Gish
To directly link to this image copy and paste below URL:
U-515B
Manufacturer or Marking
KNOX (USA)
U-515B
Size: 88mm X 117mm (3 ½ x 4 )
Example in Photo: KNOX (USA)
Photo Credit: Elton Gish
To directly link to this image copy and paste below URL:
U-517
Manufacturer or Marking
No Name (USA)
Cook (USA)
Locke (USA)
U-517
Size: 95mm X 82mm (3 ¾ x 3 ¼)
Example in Photo: No Name (USA)
Photo Credit: Jim Frustieri
To directly link to this image copy and paste below URL:
U-518
Manufacturer or Marking
No Name (Lima) (USA)
Victor Ins. Inc. (USA)
U-518
Size: 95mm X 95mm (3 ¾ x 3 ¾)
Example in Photo: No Name (Lima) (USA)
Photo Credit: Elton Gish
To directly link to this image copy and paste below URL:
U-519
Manufacturer or Marking
No Name (Lima) (USA)
LIMA (USA)
U-519
Size: 98mm X 79mm (3 x 3 ½)
Example in Photo: LIMA (USA)
Photo Credit: Elton Gish
To directly link to this image copy and paste below URL:
U-520
Manufacturer or Marking
VICTOR (USA)
U-520
Size: 152mm X 98mm (6 x 3 ⅞)
Example in Photo: VICTOR (USA)
Photo Credit: Ken Willick
To directly link to this image copy and paste below URL:
U-521
Manufacturer or Marking
No Name (New Lexington) (USA)
U-521
Size: 92mm X 101mm (3 x 4)
Example in Photo: No Name (New Lexington) (USA)
Photo Credit: Elton Gish
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U-521A
Manufacturer or Marking
No Name (USA)
U-521A
Size: 88mm X 107mm (3 ½ x 4 ¼)
Example in Photo: No Name (USA)
Photo Credit: Elton Gish
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U-521B
Manufacturer or Marking
No Name (Pittsburg) (USA)
U-521B
Size: 88mm X 107mm (3 ½ x 4 ¼)
Example in Photo: No Name (Pittsburg) (USA)
Photo Credit: Jeff Katchko
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U-522
Manufacturer or Marking
No Name (New Lexington?) (USA)
U-522
Size: 95mm X 95mm (3 ¾ x 3 ¾)
Example in Photo: No Name (New Lexington?) (USA)
Photo Credit: Elton Gish
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U-524
Manufacturer or Marking
No Name (USA)
Hartford Faience (USA)
Knox (USA)
Locke (USA)
O-B (USA)
Pinco (USA)
Victor Insulators. Inc. (USA)

NOTE: in 2008 and older reference books. There was a U-523 listed. It wis now deleted as it was a trim vacation of U-524. All U-523 Listings are now part of U-524. Also U-544A is now part to U-524
Size: 95mm X 85mm (3 ¾ x 3 )
Variations: Click on the thumbnail above to see style variations
Variations: Tap on the thumbnail above to see style variations
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U-525
Manufacturer or Marking
No Name (Pittsburg) (USA)
No Name (USA)
U-525
Size: 95mm X 88mm (3 ¾ x 3 ½)
Example in Photo: No Name (USA)
Photo Credit: Elton Gish
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U-526
Manufacturer or Marking
No Name (USA)
Victor Ins. Inc. (USA)
V (VICTOR) (USA)

NOTE: In 2008 and older reference books, there was a U-526A listed. It is now part of the listings for U-526
U-526
Size: 95mm X 95mm (3 ¾ x 3 ¾)
Example in Photo: No Name (USA)
Photo Credit: Robin Harrison
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U-527
Manufacturer or Marking
No Name (USA)
LAPP (USA)
Victor Ins. Inc. (USA)
U-527
Size: 101mm X 88mm (4 x 3 ½)
Example in Photo: No Name (USA)
Photo Credit: James Lindsey
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U-528
Manufacturer or Marking
Victor Ins. Inc. (USA)
U-528
Size: 101mm X 101mm (4 x 4)
Example in Photo: Victor Ins. Inc. (USA)
Photo Credit: James Lindsey
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U-529
Manufacturer or Marking
IEP (USA)
LOCKE R = ∞ (USA)
P.R.R. (USA)
Westinghouse (USA)
No Name (Trenton) (USA)

NOTE: In 2008 and older reference books. There was a U-527A listed. It is now part of the U-529 listing.
U-529
Size: 107mm X 107mm (4 ¼ x 4 ¼)
Example in Photo: No Name (Trenton) (USA)
Photo Credit: Matt Grayson
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U-529A
Manufacturer or Marking
No Name (USA)
No Name (Fred Locke or Victor, MLOD) (USA)
C.C.V.F. (USA)
COOK (USA)
Franklin Porcelain (USA)
Fred Locke (USA)
Locke (USA)
LOCKE R= ∞ (USA)
O-B (USA)
Pinco (USA)
THOMAS (USA)
VICTOR (MLOD) (USA)
VICTOR R= ∞ (USA)
U-529A
Size: 107mm X 107mm (4 ¼ x 4 ¼)
Example in Photo: Fred Locke (USA)
Photo Credit: Elton Gish
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U-529B
Manufacturer or Marking
Fred Locke (MLOD) (USA)
U-529B
Size: 104mm X 111mm (4 x 4 )
Example in Photo: Fred Locke (MLOD) (USA)
Photo Credit: Elton Gish
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U-529C
Manufacturer or Marking
No Name (Fred Locke or Victor, MLOD) (USA)
Fred Locke (MLOD) (USA)
U-529C
Size: 104mm X 101mm (4 x 4)
Example in Photo: Fred Locke (MLOD) (USA)
Photo Credit: Elton Gish
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U-530
Manufacturer or Marking
No Name (USA)
O-B (USA)
PINCO (USA)
Illinois (USA)
Victor Ins. Inc. (USA)
VICTOR R= ∞ (USA)

NOTE: In 2008 and older reference books, there was a U-530A Listed. All listings are now part of U-530
U-530
Size: 107mm X 114mm (4 ¼ x 4 ½)
Example in Photo: No Name (USA)
Photo Credit: Elton Gish
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U-532
Manufacturer or Marking
No Name (USA)
G.P. Co. (USA)
O-B (USA)
THOMAS (USA)
U-532
Size: 111mm X 111mm (4 x 4 )
Example in Photo: G.P. Co. (USA)
Photo Credit: Elton Gish
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U-532A
Manufacturer or Marking
No Name (USA)
Franklin Porcelain (USA)
Illinois map (259) (USA)
O-B (USA)
THOMAS (USA)
U-532A
Size: 111mm X 111mm (4 x 4 )
Example in Photo: Franklin Porcelain (USA)
Photo Credit: Fred Collier
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U-532B
Manufacturer or Marking
G.P.Co. (USA)
Knox (USA)
O-B (USA)
THOMAS (USA)
U-532B
Size: 111mm X 114mm (4 x 4 ½)
Example in Photo: O-B (USA)
Photo Credit: Fred Collier
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U-533
Manufacturer or Marking
No Name (New Lexington) (USA)
U-533
Size: 107mm X 107mm (4 ¼ x 4 ¼)
Example in Photo: No Name (New Lexington) (USA)
Photo Credit: Elton Gish
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U-534
Manufacturer or Marking
Lapp (USA)
U-534
Size: 114mm X 95mm (4 ½ x 3 ¾)
Example in Photo: Lapp (USA)
Photo Credit: FaceBook Post
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