Graphite Hearth Plate and Bottom Plate for Vacuum Furnace
Product Overview
Our graphite hearth plates and bottom plates are flat, rigid graphite slabs installed at the base of vacuum and atmosphere furnace hot zones to support work baskets, fixtures, and loads during thermal processing. Machined from high-density isostatic graphite, these plates provide a flat, dimensionally stable platform that withstands repeated heating and cooling cycles without warping. Hearth plates are critical consumable furnace components that directly impact temperature uniformity and load support integrity in vacuum brazing, sintering, and heat treatment furnaces.
At Jincheng Graphite, we manufacture hearth plates in standard rectangular and round configurations, with custom sizes and machined features such as lifting holes, support pin locations, and grooves for fixture registration. Each plate is precision-planed on both sides for flatness and parallelism, ensuring that loads sit level and furnace temperature distribution remains uniform. We also supply replacement hearth plates for major vacuum furnace brands and can reverse-engineer worn plates from samples or drawings.
Key Features
- High-density structural graphite - supports heavy loads without sagging at temperature
- Precision surface planed - flat and parallel for uniform load support
- Thermal cycle resistant - maintains flatness through hundreds of thermal cycles
- Custom sizes - rectangular or round plates cut to chamber dimensions
- Machined features - lifting holes, pin locations, and fixture grooves as required
- Low outgassing - clean vacuum performance for oxidation-sensitive loads
- Stackable design - multi-layer hearth configurations for batch processing
- Long service life - resists deformation and surface erosion over years of use
Technical Specifications
| Parameter | Value |
|---|---|
| Material | High-density isostatic graphite |
| Bulk Density | 1.78 - 1.85 g/cm³ |
| Flexural Strength | 50 - 65 MPa |
| Compressive Strength | 90 - 120 MPa |
| Max Temperature | 2200°C (vacuum/inert) |
| Standard Sizes | 300×300, 400×400, 500×500, 600×600 mm |
| Thickness | 10 - 50 mm |
| Flatness | < 0.1 mm per 300 mm |
| Parallelism | < 0.15 mm per 300 mm |
| Dimensional Tolerance | ±0.2 mm |
| Max Plate Size | 1000 × 1000 mm (assembled on request) |
| Surface Finish | Ra 3.2 µm (planed) |
Applications
- Vacuum brazing furnaces - support plates for work baskets and fixture stacks
- Vacuum sintering furnaces - hearth plates supporting powder metallurgy loads
- Heat treatment furnaces - bottom plates for carburizing and nitriding loads
- Bright annealing furnaces - flat support for stainless and alloy annealing
- Crystal growth furnaces - support plates for crucible and heater assemblies
- Laboratory furnaces - small hearth plates for research and development furnaces
Why Choose Jincheng Graphite?
- Precision planing - both faces machined for flat, parallel support surfaces
- Custom dimensions - plates cut to your exact chamber and load requirements
- Structural grade selection - recommend density based on load and temperature
- Reverse engineering - replicate worn hearth plates from measurements or samples
- Machined features - holes, grooves, and locating pins as part of the plate
- Fast delivery - standard plates ship within 7-10 business days
- Competitive pricing - factory-direct hearth plate manufacturing
- Global supply - replacement hearth plates for furnace maintenance worldwide
FAQ
Q: How do I choose the right hearth plate thickness?
A: Plate thickness depends on your maximum load and chamber span. For typical vacuum furnace loads (100-500 kg), a 20-30 mm thick plate is standard. For heavier loads or wider spans, we recommend 40-50 mm plates or multi-plate support. Tell us your load weight and chamber dimensions and we will recommend the right thickness.
Q: Can hearth plates be flipped to extend life?
A: Yes. Because both faces are precision-planed, hearth plates can be removed, flipped, and reinstalled when one side shows wear or discoloration. This typically doubles the effective service life of each plate.
Q: Do you supply round hearth plates?
A: Yes. We manufacture both rectangular and circular hearth plates for round vacuum furnace chambers. Provide your chamber inner diameter and required plate thickness, and we will quote the matching round plate.
Q: What is the lead time for custom hearth plates?
A: Standard rectangular plates in common sizes ship within 7-10 business days. Custom plates with machined features or non-standard dimensions typically require 15-20 business days.
Hot Tags: graphite hearth plate and graphite bottom plate for vacuum furnace, China graphite hearth plate and graphite bottom plate for vacuum furnace manufacturers, suppliers, factory, graphite block EDM use, graphite block for fuel cell system, graphite block for high temperature testing, graphite block for metal processing, graphite block for optical industry, machined graphite block
