Coincidentally, I just asked about the expansion coefficient of uranium
glass on a materials newsgroup but haven't seen the replies yet. The
Apparatus Drawing Project has shop drawings for a Balmer Series Spectrum
Tube and says to use a bead of uranium glass to attach the tungsten
rod to pyrex for the electrodes. Oddly enough, the CRC book (64th ed)
doesn't have the information, nor does Strong's Procedures in Experimental
My interest is in artwork and the 480C working temperature for glass to
metal seals. "Geissler tubes" and "depression era" glass. Some time on
google didn't yield results. Corning and Kimble sites did not have any
useful data. 7740 glass is a boro glass with some(1%)? dopinging of
uranium. Are you a glass blower/scientific glass fabricator. Uranium
glass also used in fabricating tubes of years gone by.
I second that, Email or better yet, call them and ask to talk with someone
for some "technical information" They're usually willing to help.
There some good scientific glass blowing books out there. But they're out of
print. You can sometimes find them at University libraries.
My favorite was written by Wheeler. Not sure of the date.
I have a copy of "The Glass Engineering Hand Book by Shand. 1958" He was a
Corning engineer. It states the following
Corning # 3321 as hard green sealing glass.
CEO 0-300 degrees C 40 x 10-7
Strain point 495 c
Annealing point 540c
Softening point 780c
We usually use uranium as an intermediate on tungsten to boro seals.
There's a bit of a trick to do it right. You need to clean the tungsten and
oxidize it prior to sealing. Is there a specific metal you're trying to
SC Glass Tech
Scam Diego, Comi-forna
Thanks Mike. Do you know if any artists are fabricating geissler tubes?
My interest is to combine phase gratings and high frequency for
displays. I also desire to see if this glass can be supplied as a bead
for glass to metalseals in a uhv vacuum application.
Thanks for the info Randy. I am looking to seal DuPont LCCC
ceramic(layered laminated green sheet) to tungsten or moly wire as
electrical feedthroughs for a uhv application. Our uhv vacuum boyos are
strict on the materials and processes for the ceramic package. Once
again my thanks.