Glass Products
GBC manufactures microscopic sized glass beads used in producing hermetically sealed packages for the electronics industry.
Using proprietary glass forming processes, GBC produces precision glass tubing and rods. These glass components are used in miniature fuse bodies, lenses for photo transistors, glass-to-metal seals used in IC packages, Erasable/Programmable Read Only Memory (Eprom) and Read Only Memory (ROM) glass lenses...and many others.
Scope of Glass Manufacturing Operations
GBC employs two unique processes to manufacture glass tubing and rod. One process is termed the "Direct Draw" process and has the ability to manufacture small quantities of glass tubing and rod to very precise tolerances.
With this process it is possible to produce a wide range of colors and opaque glass. The largest volume of product produced by the "Direct Draw" process is tubing that is cut into glass-to-metal sealing beads.
The second process is called the "Redraw" process. This process produces large quantities of continuously formed, clear glass tubing or rod. Glass tubing from this process is then cut into a variety of different sizes.
Size Range
Glass tubing and rod are made to .150" maximum outside diameter. Large diameters with small bores are possible, such as .100" O.D. by .010" I.D.
Tolerances
Normal tolerances range from ±.001" to .003" O.D. and I.D. depending on size. Tolerances are individually quoted.
Cutting
Glass tubing is diamond saw cut to length. Beads for glass-to-metal seals are normally cut to tolerances of ±.002" for small lengths and ±.003" for lengths ½ inch or longer. Score and break cutting is also available to .015" tolerance.
Special Compositions
Glasses can be formulated for unusual applications such as sealing to alloys or ceramics.
Future Products
Diode glass compositions in glass tubing and rod are under development. An alkali-free glass for "moly" sealing and dumet sealing will soon be available.
Quotations
For prompt quotations specify the following: O.D., I.D., length, tolerance, glass, color and quantity.
| Precision Glass Data | ||||||||
|---|---|---|---|---|---|---|---|---|
| Glass Code | Basic Composition | **Forms | Uses | C.T.E. x 10-7 in/in/°C | Softening Point. °C | Annealing Point. °C | Strain Point °C | Density g/cc |
| K-Glass | Borosilicate | TR | Kovar Sealing | 45 | 720 | 500 | 440 | 2.20 |
| 7052 | TR | 47 | 712 | 484 | 440 | 2.27 | ||
| x SCQ-5 (EN-1) | T | 47 | 716 | 4482 | 437 | 2.26 | ||
| ♦ 8250 | TR | 50 | 720 | 507 | 450 | 2.28 | ||
| 7070 | TR | Microwave | 32 | - | 496 | 456 | 2.13 | |
| 7740 (Pyrex®) | T | Fuse Casings | 32 | 821 | 560 | 510 | 2.23 | |
| SG-80 | Soda Lime | TR | Dumet Sealing Compression Seals Lamps | 93 | 677 | 480 | 450 | 2.60 |
| 0080 | TR | 93 | 696 | 514 | 473 | 2.47 | ||
| SCA-1 (R-6) | TR | 93 | 700 | 525 | 486 | 2.53 | ||
| ♦ 8061 | Soda Barium | TR | Compression Seals Dumet Sealing | 93 | 677 | 480 | 450 | 2.60 |
| 9013 | TR | 88 | 656 | 462 | 423 | 2.64 | ||
| SCM-5 (TM-7) | TR | 90 | 658 | 454 | 415 | 2.58 | ||
| VHX-15 | No Lead | T | Steel Dumet Compression Seals Diode Applications | 94 | 600 | - | - | 4.25 |
|
Fusite Glass Codes Corning Glass Codes |
Sem-Com Glass Codes (Kimble Glass Equivalent) Schott Glass Codes |
**Forms: T - Tubing, R - Rod |
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Properties of Some Commonly Used Metals
| Metal | Melting Pt. °C | Vacuum Maximum Operating Temp. °C | Air Maximum Operating Temp. °C | C.T.E x 10-7 in/in/°C | Thermal Conductivity Cat./Sq. Cm/Cm/°C/Xec. |
|---|---|---|---|---|---|
| Tungsten | 3350 | 3000 | 300 | 44 | 0.38 |
| Molybdenum | 2450 | 2000 | 200 | 55 | 0.35 |
| Kovar | 1450 | 1000 | 600 | 47 | 0.04 |
| Platinum | 1750 | 1600 | 1400 | 93 | 0.166 |
| Copper | 1083 | 400 | 150 | 178 | 0.092 |
| Nickel | 1452 | 900 | 400 | 145 | 0.14 |
| Dumet | 400 | 150 | 7.1 longitudinal 9.0 radial |
||
| iron | 1535 | 500 | 500 | 128 | |
| Titanium | 1800 | 1000 | 250 | ||
| Type 304 Stainless | 1426 | 800 | 800 | 178 |



