Products
Five product families, made in several grades and to your drawing. Grade, maximum temperature and tolerances are confirmed in each quotation.
01
One-end-closed and open-ended ceramic sheaths that protect thermocouples in temperature-measurement instruments and industrial furnaces.
18 protection-tube sizes from 6×4 to 26×20 mm, most in stock.
02
Single-, double- and multi-bore insulators that separate thermocouple wires and provide electrical insulation at high temperature and high frequency.
03
Open-ended process tubes, large-diameter tubes and custom tubes for laboratory, resistance, electric and heat-treatment furnaces.
04
Cylindrical, rectangular and special-shaped crucibles and boats for metallurgy, chemical processing, electronics, glass and laboratory analysis.
05
Solid round alumina rods in eight diameters from 2 to 12 mm, about 2400 mm long and all in stock, with a +0.2 mm grinding allowance on the diameter.
06
Special-shaped parts made from your drawing or sample, by slip casting, pressing, extrusion or hot pressing.
Standard sizes
63 standard sizes: 18 thermocouple protection tubes, 12 open furnace tubes and 33 single-, twin- and four-bore insulators. 45 are usually in stock and ship in about 3–7 days; the other 18 are made to order. Lengths are cut to order.
Grade: C799 alumina as standard; grade confirmed per order.
| OD × ID | Wall | Availability |
|---|---|---|
| 30 × 20 mm, Furnace tubes, open both ends | 5 | Usually in stock |
| 30 × 23 mm, Furnace tubes, open both ends | 3.5 | Usually in stock |
| 32 × 25 mm, Furnace tubes, open both ends | 3.5 | Usually in stock |
| 35 × 25 mm, Furnace tubes, open both ends | 5 | Usually in stock |
| 40 × 30 mm, Furnace tubes, open both ends | 5 | Usually in stock |
| 45 × 35 mm, Furnace tubes, open both ends | 5 | Usually in stock |
| 50 × 40 mm, Furnace tubes, open both ends | 5 | Usually in stock |
| 55 × 45 mm, Furnace tubes, open both ends | 5 | Usually in stock |
| 60 × 50 mm, Furnace tubes, open both ends | 5 | Usually in stock |
| 65 × 55 mm, Furnace tubes, open both ends | 5 | Usually in stock |
| 70 × 60 mm, Furnace tubes, open both ends | 5 | Usually in stock |
| 80 × 70 mm, Furnace tubes, open both ends | 5 | Usually in stock |
| OD × bore Ø | Wall | Availability |
|---|---|---|
| 2 × 1 mm, Single-bore insulators | 0.5 | Made to order |
| 2.5 × 1.5 mm, Single-bore insulators | 0.5 | Usually in stock |
| 3 × 2 mm, Single-bore insulators | 0.5 | Usually in stock |
| 4 × 2.5 mm, Single-bore insulators | 0.75 | Made to order |
| 5 × 3 mm, Single-bore insulators | 1 | Made to order |
| 6 × 4 mm, Single-bore insulators | 1 | Made to order |
| 8 × 5 mm, Single-bore insulators | 1.5 | Made to order |
| 10 × 4 mm, Single-bore insulators | 3 | Usually in stock |
| 12 × 7 mm, Single-bore insulators | 2.5 | Made to order |
More on alumina thermocouple insulators and multi-bore tubes
| OD × bore Ø | Availability |
|---|---|
| 2 × 0.5 mm, Twin-bore insulators | Made to order |
| 2.5 × 0.7 mm, Twin-bore insulators | Usually in stock |
| 3 × 0.8 mm, Twin-bore insulators | Made to order |
| 3.5 × 0.9 mm, Twin-bore insulators | Usually in stock |
| 4 × 1 mm, Twin-bore insulators | Made to order |
| 4.2 × 1.1 mm, Twin-bore insulators | Usually in stock |
| 4.5 × 1.2 mm, Twin-bore insulators | Usually in stock |
| 5 × 1.2 mm, Twin-bore insulators | Made to order |
| 5.5 × 1.4 mm, Twin-bore insulators | Usually in stock |
| 6 × 1.4 mm, Twin-bore insulators | Made to order |
| 8 × 1.8 mm, Twin-bore insulators | Made to order |
| 8.5 × 1.8 mm, Twin-bore insulators | Usually in stock |
More on alumina thermocouple insulators and multi-bore tubes
| OD × bore Ø | Availability |
|---|---|
| 2 × 0.4 mm, Four-bore insulators | Made to order |
| 2.5 × 0.6 mm, Four-bore insulators | Usually in stock |
| 3 × 0.6 mm, Four-bore insulators | Made to order |
| 3.5 × 0.8 mm, Four-bore insulators | Usually in stock |
| 4 × 1 mm, Four-bore insulators | Made to order |
| 4.2 × 1.0 mm, Four-bore insulators | Usually in stock |
| 4.5 × 1.1 mm, Four-bore insulators | Usually in stock |
| 5 × 1.2 mm, Four-bore insulators | Made to order |
| 5.5 × 1.3 mm, Four-bore insulators | Usually in stock |
| 6 × 1.3 mm, Four-bore insulators | Made to order |
| 8 × 1.6 mm, Four-bore insulators | Made to order |
| 8.5 × 1.6 mm, Four-bore insulators | Usually in stock |
More on alumina thermocouple insulators and multi-bore tubes
Protection tubes also come in standard lengths of 300 / 450 / 600 / 1000 mm. Other lengths, and sizes not listed here, are made to your drawing (minimum order 100 pieces for non-standard parts).
We have shipped tubes 160 mm in diameter, and single tubes 5,595 mm long.
Wall = (OD − ID) ÷ 2, from nominal sizes. Each size links to its own page with tolerances and fits.
Also made
We also make these product lines. Ask about them in your quote request.
Round, square, capillary, perforated and threaded tubes, solid-core rods, special shapes.
Ask for property data for these materials in your quote request. Published datasheets cover high-alumina and corundum.
Request a quote
Tell us the dimensions, grade and quantity. We confirm the grade, dimensions and tolerances in each quotation. Our yearly lab reports are available on request.