Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss

Kimax vs. Pyrex

2,328 views
Skip to first unread message

Jerome Graham

unread,
Jul 10, 1994, 11:21:42 AM7/10/94
to
Could anyone tell me the difference between Kimax and Pyrex?

Thanks.


Jerome

ja

unread,
Jul 10, 1994, 10:10:10 PM7/10/94
to
In article <2vp3m6$c...@nwfocus.wa.com>,

Both are used as brand names for borosilicate glasses. Kimax actually
refers to the company that makes Kimax borosilicate. They also
manufacture soda glass and chemical glassware.

Though the exact composition of Kimax borosilicate and Pyrex (Corning's
brand of borosilicate) may vary slightly, they are for all practical
purposes the same.


-John Anderson
MegaVolt Neon & Scientific
--

Paul WOOLMER

unread,
Jul 11, 1994, 4:37:54 AM7/11/94
to
Kimax is made by an american glass manufacturer and Pyrex is made by
Crown Corning, and English group. I think the glass is essentially the same.

Daniel R. Lombardi

unread,
Jul 11, 1994, 10:21:45 PM7/11/94
to
The Kimax glassware I've seen have snap caps that leak. Pyrex has glass
stoppers that don't leak.



Kevin P. Gable

unread,
Jul 13, 1994, 10:57:03 AM7/13/94
to
Although these are both borosilicate glasses of similar composition, they are
not exactly the same. For example, you cannot (successfully) fuse a piece of
Kimax to a piece of Pyrex, unless you manufacture a graded seal. However, if
you don't need to do any glassblowing, they are for all intents
interchangeable.

ja

unread,
Jul 13, 1994, 10:04:50 PM7/13/94
to
In article <gablek.2...@ccmail.orst.edu>,


Not true at all. I routinely use Kimble's "Kimax" glassware as
components of more complex all-glass apparatus - always using Corning's
"Pyrex" for all tubing. They fuse flawlessly, and inspection of the seal
under a polariscope reveals no stresses.

You must be thinking about their "R-6" glass (which is not borosilicate,
but soda-lime glass, expansion cOF 93) or their little-used N-51A - which
is a higher expansion borosilicate (cOF 47) for special uses, but not
generally used in their glassware. "KG-33" (cOF 32) is their standard
borosilicate for general labware.

-John Anderson
MegaVolt Neon and Scientific
--

Kevin P. Gable

unread,
Jul 14, 1994, 6:33:03 PM7/14/94
to
My results are different; although I can routinely blow pyrex together with no
problems, I can never get decent results with anything labelled "Kimax."
Our glassblower gets the same results; the fused junction shatters as soon as
it's cooled (annealed or not).

ja

unread,
Jul 15, 1994, 8:38:23 PM7/15/94
to
In article <gablek.3...@ccmail.orst.edu>,

Kevin P. Gable <gab...@ccmail.orst.edu> wrote:

Hmmm. Sounds like a classic case of soda-lime glass and borosilicate
(which indeed need a graded seal of 7 glasses to fuse successfully).

Compatibility of glasses for sealing to one another is based on their
expansion coefficients. Kimax KG-33 and Pyrex 7740 both have identical
coefficients (32). Even glasses with cOF's as high as 40 seal to these
glasses easily. "Nonex" with a cOF of 36 is used in nearly all
pyrex-to-metal seals (which is then sealed directly to pyrex).

When the "KIMAX" name is used by itself, then the item is made of
Kimble's KG-33 glass. If followed by a suffix it is one of their other
glasses (ie: KIMAX-51 means the item is made of N-51A glass, KIMAX-35
means the item is KG-35 glass, etc.)

Some of Kimble's smaller machine-blown containers are made of the KG-35
glass. It's cOF is 58, and indeed would need at least a Nonex
intermediate, probably a bead of Pyrex 7050 (cOF 46) as well.

luciacava...@gmail.com

unread,
Sep 30, 2017, 4:21:48 PM9/30/17
to
Can someone tell me where or who can write to show you what happened to me with my 2L KIMAX beaker ?

0 new messages