Alumina Tubes

Gain Elevated Temperature Stability with High Purity Alumina Tube Models

Sentro Tech’s alumina tubes are 99.5% to 99.8% high purity and offer elevated temperature stability. Alumina tubes are available in custom sizes, including American and Metric, and offer a low material cost.

Minerals containing alumina make up nearly 15% of the earth’s crust. This makes it practically inexhaustible and versatile. Alumina provides the combination of low thermal expansion, superior thermal conductivity and high compressive strength making it thermal shock resistant and the ideal product for alumina tubes. Our alumina tube models have elevated dielectric properties and are gas tight providing a higher vacuum or protective atmosphere when at an extreme temperature.

These alumina tubes offer:

  • Extreme high temperature stability under reducing, inert and high vacuum condition under high temperature up to 1800°C.
  • Extreme wear and abrasion resistance.
  • Chemical corrosion resistance under high temperature.
  • High dielectric properties.
  • Gas tight for many applications to provide protective atmospheres or high vacuum at high temperature to eliminate contamination or impurity.
  • Low material cost and custom size available.
  • Available Tube Diameter From 3/16″ to 9″ for American size and 2 mm to 150 mm.
  • Available Tube Length: From 1″ ( 25mm) To 72″ ( 1828mm).
  • Most items are in Stock and can be delivered in 1-3 days.
  • Sentro Tech also offer volume discount for all listed sizes if order quantity is more than 5 pieces for same size.

Typical Physical Properties of Alumina Tubes

Composition 99.80% AL2O3 99.5% AL2O3
Bulk Specific Gravity (g/cc) 3.9 3.8
Color Ivory Ivory
Impenetrability Gas Tight Gas Tight
Dye Penetration A.S.T.M. Tight Tight
Flexural Strength (psi) 70,000 50,000
Compressive Strength (psi) 370,000 350,000
Tensile Strength (psi) 43,000 33,000
Maximum Working Temperature 1800°C 1750°C
Likely Sag Temp. Unsupported Tube* 1600 oC 1600 oC
Thermal Conductivity 24oC 230 200
(BTU-in/ft2-hr-oF) 800oC 60 50
Dielectric Strength 24oC V/Mil 300 270
Thermal Expansion (per oC x 10-6) 8 8.4
(24oC-1000 oC)    
Hardness (Moh’s scale) 9 9
* Temperature at which an empty tube, 1 1/4″ diameter, suspended across an 18″ span, will sag 1/4″ in 1 hour.
Where sag is not acceptable, tubes must be adequately supported along the full length.

alumina tube measurements