High-Purity Carbon & Graphite
Graphite Blocks
High-Purity Graphite Blocks with Carbon Content of 99.9% and Above for Furnaces, Foundry, Chemical, Electronics and Nuclear Applications
≥99.9%
Fixed carbon content
3000°C
Graphitization temperature
4
Forming methods available
Custom
Sizes and machining
Graphite blocks are solid graphite materials with a fixed carbon content of 99.9% and above. They are used as the base material for flexible graphite sealing products, nuclear graphite, crucibles that replace platinum for melting chemical reagents, lubricant bases, silicon carbide furnaces, graphite and resistance furnace linings, conductive materials and impermeable graphite heat exchangers.
GraphiteCentral supplies graphite blocks in all major grades — isostatic, molded, extruded and vibration molded — for the electronics, semiconductor, metallurgy, chemical, steel and machinery industries. Blocks are available as raw stock or machined to customer drawings, including sintering molds for diamond tools and components for high-temperature industrial furnaces.
How Are Graphite Blocks Made?
Graphite blocks are produced from carbon raw materials such as petroleum coke mixed with a pitch binder. The mixture is formed by isostatic pressing, compression molding, extrusion or vibration molding, then carbonized at 800–1200°C and graphitized at 2500–3000°C, converting the carbon into a dense, ordered graphite structure.
Pitch impregnation reduces porosity and increases density and strength, while high-temperature purification removes impurities for semiconductor, monocrystalline silicon and nuclear applications. The finished blocks combine high purity, thermal shock resistance, electrical conductivity and excellent machinability.
Why Choose Our Graphite Blocks?
High Purity
Fixed carbon content of 99.9% and above, with further purification available for demanding applications.
Thermal Shock Resistance
Low thermal expansion and stable performance under rapid heating and cooling in furnace environments.
Electrical Conductivity
Excellent conductivity for resistance furnace linings, electrodes and conductive components.
Chemical Stability
Resistant to acids, alkalis and corrosion — suitable for chemical processing equipment and heat exchangers.
Excellent Machinability
Easily machined into molds, dies, crucibles, sintering trays and precision custom components.
High Temperature Performance
Maintains strength and stability at extreme temperatures in vacuum and non-oxidizing atmospheres.
Graphite Block Types by Forming Method
Isostatic Graphite Blocks
Pressed uniformly from all directions for outstanding isotropy, fine grain and the highest density — the premium grade for semiconductor and precision applications.
Molded Graphite Blocks
Compression molded blocks with high density, fine grain and excellent machinability at a balanced cost.
Extruded Graphite Blocks
Continuously extruded blocks and rods — a cost-effective option for electrodes, heating elements and large parts.
Vibration Molded Blocks
Large, uniform blocks compacted by vibration — ideal for big crucibles, furnace linings and heavy-duty applications.
Graphite Block Grain Sizes
| Grain Type | Grain Size | Porosity | Typical Applications |
|---|---|---|---|
| Fine Grain | 0.0025–0.127 mm | 5–15% | Crucibles, casting dies, heating elements, seals, precision parts |
| Medium Grain | 0.5–1.6 mm | 12–20% | Furnaces, trays, extrusion guides, self-lubricating bearings |
| Coarse Grain | 1.0–6.35 mm | 12–20% | Large crucibles, ingot molds, pouring troughs |
Custom Sizes & Machining
Graphite blocks can be cut, machined and purified according to customer drawings, dimensions, grade and purity requirements. Send us your specifications for the right grade recommendation and pricing.
Need graphite blocks in a specific grade, size or purity? We ship from USA stock.
Common Applications
Furnaces & Metallurgy
- Silicon carbide and graphite furnaces
- Resistance furnace linings
- Conductive furnace materials
- Steel and non-ferrous metallurgy
Foundry & Powder Metallurgy
- Casting molds and dies
- Sintering molds for diamond tools
- Crucibles replacing platinum
- Sintering trays and fixtures
Chemical, Energy & Nuclear
- Impermeable graphite heat exchangers
- Nuclear graphite components
- Flexible graphite sealing base material
- Electronics and semiconductor processing
Frequently Asked Questions
What is a graphite block?
A graphite block is a solid graphite material with a fixed carbon content of 99.9% and above, used as raw stock for machining or directly in furnaces, molds, heat exchangers and sealing products.
How are graphite blocks made?
Carbon raw materials such as petroleum coke are mixed with a pitch binder, formed by isostatic pressing, molding, extrusion or vibration molding, carbonized at 800–1200°C and graphitized at 2500–3000°C. Pitch impregnation and purification further improve density and purity.
What types of graphite blocks are available?
We supply isostatic, molded, extruded and vibration molded graphite blocks in fine, medium and coarse grain grades. The right type depends on required density, isotropy, size and budget.
Can graphite blocks be machined to custom dimensions?
Yes. Graphite blocks are easily machined by CNC milling, turning, drilling and cutting. We supply both raw blocks and finished components manufactured to customer drawings and tolerances.
What are graphite blocks used for?
Typical uses include silicon carbide and resistance furnaces, casting and sintering molds, crucibles, impermeable heat exchangers, nuclear graphite, conductive components, and base material for flexible graphite sealing products.
Explore Other Graphite Products
Graphite Rod
Graphite Crucible
Molded Graphite
Looking for Graphite Blocks?
GraphiteCentral holds one of the largest graphite inventories in the USA and supplies high-purity graphite blocks in all grades, sizes and purities — raw stock or machined to your drawings.