Extruded 99.7% high-purity alumina 2-bore, 4-bore, and 6-bore capillary insulator rods and beads for Type R, S, B, K, and C high-temperature thermocouples and UHV feedthroughs.
Even trace silica (SiO2) or iron impurities in low-grade ceramic insulators vaporize above 1,200 °C and poison Platinum-Rhodium (Type R/S/B) and Tungsten-Rhenium (Type C/D) thermocouple junctions, causing severe EMF calibration drift.
Our 99.7% C799 recrystallized alumina multi-bore insulators contain <0.1% SiO2 and maintain high electrical volume resistivity (>10⁸ Ω·cm at 1,000 °C) up to 1,750 °C in air, vacuum, or inert gas.
| Property / Metric | Nominal Reference Value (Grade Dependent) |
|---|---|
| Material Grade | 99.7% α-Al2O3 (C799 Low-Silica) |
| Bore Configurations | Single, 2-Bore, 4-Bore, 6-Bore, & Oval |
| Standard OD Range | 0.8 mm, 1.2 mm, 1.6 mm, 2.4 mm, 3.0 mm, 4.0 mm, 4.7 mm, 5.5 mm, 6.35 mm, 8.0 mm |
| Standard ID Bore Range | 0.25 mm to 2.5 mm |
| Max Working Temp | 1,750 °C |
Reference values reflect typical sintered, fused, or wrought grades. Exact batch test figures are confirmed on your written quotation and accompanying lot Certificate of Analysis.
Specify number of bores (2-bore or 4-bore), outer diameter (OD), inner bore diameter (ID), length (or cut bead length), and quantity.
Include target quantity, destination country/postal code for express air freight calculation, and any special cleanroom bagging or certification requests.
Prepare Multi-Bore Alumina (99.7% Al2O3) Thermocouple Insulator Beads & Rods RFQ ↗Complementary furnaceware, substrates, PVD consumables, and refractory hardware frequently ordered together.
TB-AL2O3-TUImpervious high-purity sintered alumina furnace and process tubes for tube furnaces, CVD/annealing, and high-temperature thermal systems.
TB-WRE-TCHigh-purity Matched EMF Calibration Grade (ASTM E988 / IEC 60584 Type C & Type D) Tungsten-Rhenium thermocouple wire (type c, type d & type g) & probes (W5Re / W26Re & W3Re / W25Re, CAS 7440-15-5) engineered for ultra-high-temperature vacuum furnaces, crystal growth, semiconductor processing, and corrosive environments.
TB-AL2O3-CRHigh-purity cylindrical, conical, and rectangular alumina crucibles and matching lids for high-temperature melting, calcination, and gravimetric analysis.
TB-HBN-MCHot-pressed hexagonal boron nitride (h-BN) crucibles, rods, plates, and precision CNC components combining extreme thermal shock resistance, molten-metal non-wetting, and electrical insulation.
Submit your purity grade, geometry, quantity, and documentation requirements. Every order includes the producing mill's batch Certificate of Analysis (COA) and pre-shipment dimensional verification.