What parts are EXACTLY the same and built by the same machine if so?

I would guess the bulb, the insides and the base are made by the same machinery. The etch is probably done now by a continuous ink printer.

I will check closely when I can, but I know the filament in the Marvel is mounted lower than the American, its down near the neck area. The bite marks in the glass well where the base fits on might be the same in both. The Marvel has an early 60s50s style Westinghouse base and a Corning Glass outer envelope. The American has a modern Sylvania base and the glass is also from Sylvania but its said they use the Corning ribbon machinery so its basically the same glass.

Is Supreme the same supreme that makes the "EXTRALIFE" 5000 hour 130v bulbs? The new EXTRALIVES are made by Satco apparently...

The current Supreme is a new company, but there is some connection with the old Supreme. The family who sold the old Supreme now works with Satco and offer these new Supremes sourced from China.

Also, I just examined the two bulbs above. The stem construction and stem press seem a bit different, but the bite marks in the glass well look to be the same. Prolly the same Sealex machine.

Dave, great addition, as always.

I have come across many recent long-life A19s (Guaranteeds and I believe some American Light Bulbs) that appear to be made on the same line as the Sylvania Rough Service XLs. As you note, their light center length is shorter than the usual (the filament is closer to the base) and they have the same clean "dot" welds on the base where virtually no solder is used. Even the etch on the Sylvanias looks similar to some of the Guaranteeds I have.

It's been my experience that I can group these lamps into 3 or 4 apparent manufacturers:

- Sylvania (always has the tiny "dot" welds on the base)
- Trojan/Hytron (usually well made but frequently sloppy etches) - Kayline gets their bulbs from Trojan
- Aero-Tech - Well made with clean, tiny etches (labels) but uneven acid etching finishes and spotty welds
- Others that have sloppy welds on the bases

Any other observations?

Alex

I have some of these Guaranteeds and Americans with the welded lead on the upper rim rather than soldered. I think they are Mullins bulbs though, if you look closely you can see differences between the Sylvanias and these. They have different machines making bulbs with slightly different design features. I think Trojan, American, and Sylvania are the only three manufacturers making long life commercial grade bulbs in the USA nowadays. In the past you had the following:

Duro-Test (Duro-Mex still makes bulbs in Mexico on the old DT machinery)
Action Tungsram (yes they made the USA made bulbs themselves and they also made long life bulbs with supported CC6 filaments)
Energex (very good bulbs, they made the Torch bulbs, closed in 1980)
Solar (nicely made bulbs similar to Energex, sold to Philips in 1980)
Pennsylvania Illuminating Corp (they made the crude bulbs that nudelsoup on eBay has sold)
Durelco
Marvel (now American)
Supreme (now American)
Philips (Industrial Service line, various longlife bulbs)
Westinghouse (Industrial Service)
GE (Survivor)
Verd a ray
Lustra (VAR and Lustra sold to Philips)

There were prolly more. The above ones are what I can remember offhand.

That's a great summary, Dave. Thanks for sharing your knowledge.

I wish we lived closer to each other so we could share our collections.