Alumina ceramic rotary indexing tables are designed for precise rotational positioning in high-precision equipment, including laser marking stations, CNC systems, and automated inspection platforms. Made from ≥95% alumina, the material offers exceptional hardness, dielectric strength, and thermal resistance, making it ideal for harsh industrial conditions or cleanroom environments.
Two project types come up most often. For a new machine, the plate geometry is set around the station layout, fixture mass and motion cycle. For a replacement or revision, the interfaces that establish fit are preserved and only the worn or changed functional features are redrawn. Both paths are handled the same way: the drawing, the grade and the acceptance method are agreed before machining starts.
Alumina Rotary Indexing Table Specifications
| Alumina Rotary Indexing Table | ||
| Item No. | Diameter (mm) | Thickness (mm) |
| AT-YHL-IW01 | Customize | |
Alumina Rotary Indexing Table Properties
The three tables below describe the six dense alumina grades under the stated test conditions. They are material-selection data: the finished plate's flatness, runout, load capacity and insulation are set by the drawing and the assembly, not by these values.
Mechanical Properties
| Grade | Al₂O₃ | Density (g/cm³) | Flexural strength (MPa, 20°C) | Compressive strength (MPa) | Elastic modulus (GPa) | Fracture toughness (MPa·m^0.5) | Hardness |
|---|---|---|---|---|---|---|---|
| AD-ALU-950 | 95% | 3.75 | 280 | 2000 | 340 | 3.0 | Mohs 9 |
| AD-ALU-960 | 96% | 3.70 | 300 | 2000 | 275 at 20°C | 3.5 at 20°C | 1600 HV1 |
| AD-ALU-990 | 99.0% | 3.80–3.91 | 300–320 | 2400 | 355 | 3.3 | Mohs 9 |
| AD-ALU-995 | 99.5% | 3.90–3.92 | 320–350 | 2400 | 365 | 3.5 | Mohs 9 |
| AD-ALU-997 | 99.7% | 3.94 | 330 | 2500 | 370 | 3.6 | Mohs 9 |
| AD-ALU-999 | 99.9% | 3.94 | 315–340 | 2558–2900 | 359–375 | 3.8–4.2 | Mohs 9 |
Strength and modulus are inputs to a plate calculation; they are not a payload rating for a station. Mohs and HV1 are different hardness scales and are not converted into each other.
Thermal Properties
| Grade | Thermal conductivity (W/(m·K)) | Linear expansion (×10⁻⁶/K) | Material temperature selection reference (°C) |
|---|---|---|---|
| AD-ALU-950 | 18–25 at 25°C | 7.6, 25–800°C | 1400 |
| AD-ALU-960 | 25 at 20°C | 8.2, 25–1000°C | 1600, maximum in air |
| AD-ALU-990 | 24 at 25°C | 7.2, 25–800°C | 1600 |
| AD-ALU-995 | 30–38 at 25°C | 7.6, 25–800°C | 1650 |
| AD-ALU-997 | 35–40 at 25°C | 7.6, 25–800°C | 1700 |
| AD-ALU-999 | 35–42 at 25°C | 7.6, 25–800°C | 1750 |
The temperature reference is a material limit. The installed plate usually also carries fasteners, a hub, seals or adhesive, so the working temperature of the assembly is set by those parts and by the temperature field across the plate, not by the ceramic alone.
Electrical Properties
| Grade | Dielectric strength (kV/mm at test thickness) | Relative permittivity (1 MHz) | Loss factor tanδ (1 MHz) | Volume resistivity (Ω·cm) |
|---|---|---|---|---|
| AD-ALU-950 | 10 at 5 mm | 9.4 at 25°C | 0.0004 at 25°C | >1 × 10¹² at 20°C |
| AD-ALU-960 | 8.3 AC at 6.35 mm | 9.0 at room temperature | 0.0002 at 20°C | 1 × 10¹⁴ typical |
| AD-ALU-990 | 10 at 5 mm | 9.6 at 25°C | 0.0006 at 25°C | >1 × 10¹⁴ at 20°C |
| AD-ALU-995 | 10 at 5 mm | 9.7 at 25°C | <0.0001 at 25°C | >1 × 10¹⁴ at 20°C |
| AD-ALU-997 | 10 at 5 mm | 9.8 at 25°C | <0.0001 at 25°C | >1 × 10¹⁴ at 20°C |
| AD-ALU-999 | 10 at 5 mm | 9.8 at 25°C | <0.0001 at 25°C | >1 × 10¹⁴ at 20°C |
Dielectric strength is a test-piece value at the stated thickness; it does not multiply up to a working voltage for the plate. Insulation of the finished station also depends on hole edges, grooves, electrodes, creepage distance, contamination, humidity and grounded parts near the face.
Choosing the Plate for Your Indexer
- Start with the application. Prioritize insulation for electrical testing, thermal expansion and conductivity for heated stations, or hardness and surface finish for wear resistance. Alumina purity alone is not enough.
- For new machines, define the geometry. Provide the station layout, plate dimensions, center register and mounting holes. Include fixture weight, loads and center of gravity to determine thickness and support.
- For replacements, check the interfaces. Supply measurements and photos of the existing plate, noting wear and required changes. Replacing metal with ceramic may require different edge details, supports and tightening procedures.
- Confirm the grade with the drawing. We review the properties that matter most to your application, together with mounting details and inspection requirements.
Alumina Rotary Indexing Table Packaging
- Each alumina ceramic rotary indexing table plate is individually wrapped in soft protective film to prevent surface scratches.
