Plugs   Tunnels   Omegas   Tusks   Belly   Tapers   Claws   Twists   Spirals   [ Introduction ][ Questions ][ Mailorder ][ Wholesale ][ E-mail ][ Links ] Is it O.K. to wear your pyrex jewelry in      my tongue, nipple, or genital piercing ? NO! We will not provide advice regarding glass in tongue, nipple, or genital piercings. If you put it anywhere other than your ears or nose, we don't want to know about it!   What the hell is Pyrex® exactly ? The Corning Glass Company of New York was established in 1868. Among their first products were colored lenses for railroads and the earliest light bulbs. Much later they formulated Pyrex® brand glass, one of the most significant developments in glass technology this century. Pyrex glass a.k.a. "Corning 7740" set the worldwide standard for scientific and medical glasses. Its resistance to large temperature shifts and chemical reactions have made it a laboratory mainstay.   Shouldn't I be worried about breakage ? Not really. Pyrex® brand borosillicate glass was developed by Corning specifically for its thermal and mechanical durability. We kiln anneal all of our finished jewelry overnight to remove any stress from the glass. Regular art glass (a.k.a. "soft glass") can't compare to the strength of Pyrex. Any glass can break of course and regardless of your jewelry choice, always take care to avoid trauma to your piercing. If your Pyrex does break, it should snap in two rather than shattering like most glasses.   Doesn't glass have lead and other metals ? Unlike many varieties of art glass, Pyrex® is 100% lead-free. The Northstar colored glass we use does contain a variety of metals, but look closely and you'll notice that all color work is encased in a layer of clear. Pyrex glass is medical grade and completely non-reactive with the human body.   What is annealing and why is it important      to the production of glass body jewelry ? Annealing is the process of eliminating internal stresses that occur during the shaping of handblown glass. Some annealing can be acheived in the flame, but superior glass will always be oven annealed. Kiln annealing is just as important to glassworking, as autoclaving is to body piercing. If the internal stresses aren't removed with this process, the eventual alternative means cracking along these stress lines. Pyrex that is well formed, and kiln annealed at approximately 565°C is extremely durable.   Is your jewelry autoclave safe ? Definitely. Pyrex® was originally formulated to withstand thermal shock created by sudden and extreme shifts in temperature.     Properties of Pyrex® Glass a.k.a. Corning 7740 Coefficient of expansion x10-7 33 Working point (104 poise) °C 1220 Softening point (6x107 poise) °C 820 Annealing point (1013 poise) °C 565 Thermal conductivity W/mK at 20°C 1.14 Density g/cm3 2.23   Chemical Composition of Pyrex® Glass SiO2  - 80.5 % Al2O3 - 2.2 Cl       - 0.10 B2O3 - 12.9 K2O   - 0.4 MgO   - 0.05 Na2O - 3.8 CaO   - 0.10 Fe2O3 - 0.04     All text, photos, and graphics within TribalGlass.com are the property of Tulsa Body Jewelry and may not be reproduced without permission.