Our precision glass tubes with a calibrated inner diameter are made of borosilicate glass and have excellent chemical and physical properties. The use of borosilicate has many advantages, most notably minimal thermal expansion and insensitivity to rapid temperature changes. The high resistance to acids, alkalis and organic substances enables a wide range of applications in medical technology, laboratory applications and analytics. We can supply the high-precision glass tubes with a diameter range of 5 – 50 mm and with tolerances in the micrometer range.
Special properties of calibrated precision glass tubes
- calibrated inner diameter
- high thermal shock resistance
- refractory glass tube
- minimal thermal expansion
- corrosion resistant glass
- clear and almost colorless glass tubing
- neutral with aggressive chemicals
- very good resistance to acids, alkalis and organic substances
- low specific glass weight
- high UV transmission & good IR transmission
- good scratch and abrasion resistance
- high elasticity and mechanical strength
- versatile machinable glass tube
Typical applications
- chemical and waste water plants
- sight glasses and viewing windows – even at high temperatures
- glass tubes for mushroom heaters and infrared radiators
- glass tubes for lamps and luminaires
- measurement, control and sensor technology
- attachment glasses for powerful light sources
- environmental technology
- arts and crafts
- photovoltaic glass tubes
- glass for biotechnology and medical technology
- laboratory glass and glass tubes for glassblowers
Chemical properties
Chemical composition: 81% SiO₂ – 13% B₂O₃ – 4% Na₂O/ K₂O – 2% Al₂O₃
Hydrolytic resistance: Water resistance class HGB 1, Acid class S 1, Alkali class A 2
Physical properties
Density: 2.23 g/cm³
Refractive index: ω=1.473
Transformation temperature Tg: 525 °C
Young’s modulus of elasticity: 64 · 10³ N · mm²
Mean linear thermal expansion coefficient: 3.25 x 10-6/K (20-300 °C) (according to ISO 7991)
Electrical properties
Dielectric resistance: 4.6 (1 MHz, 25 °C )
Logarithm of volume resistance: 8.0 Ω × cm (250 °C), 6.5 Ω × cm (350 °C)
