An alumina threaded rod is a ceramic fastener — a dense alumina rod with an external metric (M2–M18) or imperial thread, full or double-end, that takes ceramic nuts and washers and can be tightened and removed like a metal screw, while staying electrically insulating, non-magnetic, heat- and corrosion-resistant and low-contamination. It is a threaded fastener (not a plain non-threaded ceramic locating rod), and alumina is a brittle material — it has no metal-like yield, so assembly torque and preload must be controlled rather than tightened like a steel bolt.
Alumina Threaded Rod Benefits
- Secure Mechanical Fastening at High Temperatures
The threaded design allows stable fastening and load-bearing in furnaces and lab setups, avoiding loosening where metal screws fail above 1200°C. - Precise Alignment and Assembly Compatibility
Machined threads (M2–M18, tolerance ±0.2 mm) enable accurate alignment with alumina nuts and washers, ensuring repeatable installation in analytical instruments and furnace structures. - Reduced Particle Contamination
Unlike metal fasteners that oxidize or shed particles at high heat, alumina threaded rods maintain surface integrity, protecting sensitive laboratory and semiconductor processes. - Longer Service Life in Aggressive Environments
The combination of ceramic material and threaded locking function minimizes replacement cycles in corrosive chemical setups and continuous-operation machinery.
Choose Alumina Threaded Rod When Metal Fasteners Are Not the Right Fit
Need reliable fastening together with electrical insulation at elevated temperatures? Alumina threaded rods are designed for assemblies where metal fasteners may introduce conductivity, corrosion, magnetism, or unwanted metal contact.
A Strong Fit For
- High-temperature insulated fastening
- Electrical isolation between components
- Non-magnetic assemblies
- Selected corrosive environments
- Applications requiring reduced metal contact
Consider Another Material When
- The joint is exposed to impact or bending
- Frequent retightening is required
- High shock or preload is expected
- Steel-like torque and ductility are essential
Ceramic vs. Metal Fasteners
- Alumina threaded rods stay electrically insulating, non-magnetic, corrosion-resistant and low-contamination at high temperature, where metal screws can conduct, oxidize, lose strength or corrode.
- Metal fasteners remain the choice where high tensile or impact strength, ductility or low cost matter most.
Alumina is brittle and torque-limited, so it suits insulated, non-magnetic or corrosive joints with controlled assembly torque — not high-impact or heavily preloaded connections.
Alumina Threaded Rod Properties
| Property | Unit | 96% Al₂O₃ | 99% Al₂O₃ | 99.5% Al₂O₃ | 99.6% Al₂O₃ | 99.7% Al₂O₃ | 99.8% Al₂O₃ | 99.9% Al₂O₃ | 99.99% Al₂O₃ |
| Alumina content | % | 96 | 99 | 99.5 | 99.6 | 99.7 | 99.8 | 99.9 | 99.99 |
| Density | g/cm³ | 3.6-3.75 | 3.83 | 3.89 | 3.91 | 3.92 | 3.93 | 3.94 | 3.98 |
| Color | – | white | Ivory | Ivory | Ivory | Ivory | Ivory | Ivory | Ivory |
| Water absorption | % | 0 | 0 | – | 0 | 0 | 0 | 0 | 0 |
| Young’s modulus (Elastic modulus) | GPa | 300 | 350 | 375 | 356 | 357 | 358 | 359 | 362 |
| Shear modulus | GPa | – | – | 152 | – | – | – | – | – |
| Bulk modulus | GPa | – | – | 228 | – | – | – | – | – |
| Poisson’s ratio | – | – | – | 0.22 | – | – | – | – | – |
| Compressive strength | MPa | 1910 | 2210 | 2500 | 2552 | 2554 | 2556 | 2558 | 2570 |
| Flexural strength | MPa | 260 | 300 | 340 | 345 | 346 | 347 | 348 | 365 |
| Fracture toughness | MPa·m¹ᐟ² | – | – | 4 | – | – | – | – | – |
| Hardness | GPa | 14.5 | 17 | 17 | 23 | 24 | 25 | 26 | 30 |
| Thermal conductivity | W/m·K | 20 | 31 | 31 | 31-33 | 31-33 | 31-33 | 31-35 | 31-35 |
| Thermal shock resistance ΔT | °C | – | – | – | 222 | 223 | 224 | 225 | 228 |
| Maximum use temperature (no load) | °C | 1450 | 1680 | ≤1750 | 1755 | 1760 | 1765 | 1770 | 1800 |
| Coefficient of thermal expansion | 10⁻⁶/°C | 7.6 | 7.6 | 7.6 | 7.6 | 7.5 | 7.5 | 7.4 | 7.4 |
| Volume resistivity | Ω·cm | >1×10¹⁴ | >1×10¹⁴ | >1×10¹⁴ | >1×10¹⁴ | >1×10¹⁴ | >1×10¹⁴ | >1×10¹⁴ | >1×10¹⁴ |
| Dielectric constant (relative permittivity) | – | 9.2 | 9.5 | 9.8 | 9.83 | 9.84 | 9.85 | 9.86 | 9.92 |
| Dielectric strength | kV/mm | 15 | 19 | 16.9 | 23.2 | 23.4 | 23.6 | 23.8 | 24 |
| Dissipation factor (loss factor @ 1 kHz) | – | – | – | 0.0002 | – | – | – | – | – |
Alumina Threaded Rod Specifications
As a professional alumina threaded rod factory in China, we supply both standard stock and custom parts with fast delivery. The following tables show standard and custom sizes.
Type 1
| Type 1: Alumina Threaded Rod | ||||
| Item No. | Diameter (mm) | Slot width (mm) | Length (mm) | Purity |
| AT-YHL-LWB1001 | 6 | 0.8 | 100-500 | 95% |
| AT-YHL-LWB1002 | 8 | 1 | ||
| AT-YHL-LWB1003 | 10 | 1.5 | ||
| AT-YHL-LWB1004 | 10 | 5 | ||
| AT-YHL-LWB1005 | 12 | 2 | ||
| AT-YHL-LWB1006 | 14 | 2.5 | ||
| AT-YHL-LWB1007 | 16 | 5 | ||
| AT-YHL-LWB1008 | 18 | 5 | ||
Type 2
| Type 2: Alumina Threaded Rod | ||||
| Item No. | Diameter of Thread (mm) | Length of Thread (mm) | Total Length (mm) | Purity |
| AT-YHL-LWB2001 | M2 | Customize | 100-800 | 99% |
| AT-YHL-LWB2002 | M2.5 | |||
| AT-YHL-LWB2003 | M3 | |||
| AT-YHL-LWB2004 | M3.5 | |||
| AT-YHL-LWB2005 | M4 | 30 | ||
| AT-YHL-LWB2006 | M5 | 30 | ||
| AT-YHL-LWB2007 | M6 | 30 | ||
| AT-YHL-LWB2008 | M8 | 30 | ||
| AT-YHL-LWB2009 | M10 | 30 | ||
| AT-YHL-LWB2010 | M12 | Customize | ||
| AT-YHL-LWB2011 | M14 | |||
| AT-YHL-LWB2012 | M16 | |||
| AT-YHL-LWB2013 | M18 | |||
Type 3
| Type 3: Alumina Threaded Rod | ||||
| Item No. | Diameter (mm) | Diameter of Thread (mm) | Total Length (mm) | Purity % |
| AT-YHL-LWB3001 | 6 | M4 | 200 | 99 |
| AT-YHL-LWB3002 | 10 | M8 | 450 | 99 |
| AT-YHL-LWB3003 | 12 | M8 | 400 | 99 |
| AT-YHL-LWB3004 | 20 | M12 | 450 | 99 |
| AT-YHL-LWB3005 | 30 | M18 | 360 | 99 |
*Note: The tables above show only some standard specifications. For additional specifications, please refer to the complete product catalogue or contact us for customization.
Alumina Threaded Rod Packaging
- Individually packed in PE bags to help prevent contamination
- Foam protection inside the carton for international shipping
- Optional ceramic nuts and washers are available as accessories
