Views: 0 Author: Site Editor Publish Time: 2026-07-23 Origin: Site
For cemented carbide manufacturers, powder metallurgy companies, and operators of vacuum heat treatment furnaces, uneven heating, workpiece cracking, and the accumulation of volatiles during high-temperature sintering are the most challenging production issues.
Ordinary solid graphite plates cannot address the problem of gas circulation within the sealed furnace chamber, which directly leads to a decline in the yield rate of finished products and frequent wear and replacement of graphite trays. Drawing on 10 years of experience in advanced graphite processing, our factory has specifically developed customized porous graphite discs (also known as perforated sintered graphite plates). These are manufactured using MSS80 and MSS85 series 25μm fine-grain isostatic graphite billets and can be designed with diverse hole patterns, including round holes, square holes, micro-holes, notches, and slots.
This article provides a comprehensive breakdown of material grades, structural advantages, application compatibility standards, customization specifications, and key points to avoid pitfalls during procurement, helping global buyers select graphite discs that are compatible with their specific furnace models.
Porous graphite discs are circular high-temperature load-bearing components precision-machined via five-axis CNC drilling from high-density isostatic graphite billets. Unlike solid graphite plates, these discs feature uniformly distributed through-holes across their surface, creating unobstructed gas flow channels within the sintering furnace. During the sintering processes of tungsten-cobalt cemented carbide, cubic boron nitride (CBN) diamond, and metal powders, the cobalt binder and organic additives within the green body will precipitate and volatilize at high temperatures; The through-holes in the graphite discs rapidly vent these volatile impurities, preventing defects such as segregation, pitting, and deformation in the sintered parts. At the same time, the porous structure ensures balanced heat conduction, guaranteeing uniform heating across every workpiece on the disc and significantly reducing the scrap rate.
Our factory’s design library contains dozens of proven hole configuration solutions: large circular holes for high-volume cemented carbide blanks, fine micro-holes for high-purity alloy production, square grid patterns to meet the load-bearing requirements of multi-layer stacking, notched discs for furnace positioning, and countersunk discs for the assembly of complete graphite component sets.
The grade of the base material used in porous graphite discs directly determines their thermal shock resistance, mechanical strength, and pore wall integrity at high temperatures. Ningheda uses three grades of isostatic graphite billets, with each grade corresponding to different operating strength requirements:
Parameter | MSS80 | MSS85 | MSS90 |
Bulk Density | ≥1.82 g/cm³ | ≥1.85 g/cm³ | ≥1.90 g/cm³ |
Compressive Strength | ≥70 MPa | ≥80 MPa | ≥90 MPa |
Flexural Strength | ≥35 MPa | ≥38 MPa | ≥42 MPa |
Porosity | ≤17% | ≤14% | ≤11% |
Ash Content | ≤0.06% | ≤0.05% | ≤0.03% |
Max Temp | 1500℃ | 1600℃ | 1800℃ |
Recommended Use | Regular sintering | Heavy-load sintering | Ultra-high temp metallurgy |
MSS80 is suitable for conventional cemented carbide sintering (1400–1500°C) and offers the best cost performance;
MSS85 strikes a balance between cost and performance, with a 17% increase in compressive strength, making it suitable for workpieces with higher packing densities;
MSS90 has a density of 1.90 g/cm³ and a porosity of only 11%; it maintains structural integrity even during tungsten powder metallurgy at 2000°C, making it a cost-effective alternative to molybdenum plates.
Key Note: The ash content can be further purified to 30 ppm, making it suitable for applications requiring extremely high purity, such as vacuum brazing.
Many buyers mistakenly believe that the higher the porosity, the better the gas permeability. In fact, porosity must be designed in conjunction with three factors: sintering temperature, workpiece weight, and protective atmosphere flow rate:
Condition | Recommended Rate | Reason |
Low-temp sintering + high H₂ flow | 25–35% | Enhanced convective heat transfer |
High-temp sintering + heavy workpieces | 15–22% | Ensure tray structural strength |
Molten metal filtration | 15–20% | Optimize inclusion trapping efficiency |
Vacuum brazing (no forced flow) | 20–25% | Balance temperature uniformity and strength |
Balanced Porosity & Mechanical Strength Design: Many small graphite processing plants have focused solely on achieving high porosity to improve air permeability, resulting in pore walls that are too thin and prone to fracturing under load. Our technical team optimizes hole spacing and diameter based on the load-bearing capacity of our customers’ furnaces, balancing air permeability with disc rigidity. The MSS85 high-density model has a minimum porosity of 11% and supports multi-layer stacking of heavy carbide blanks without warping or cracking, even after long-term repeated heating and cooling cycles.
Ultra Precise CNC Machining Tolerance: Imported five-axis CNC drilling equipment maintains hole position deviations within ±0.03 millimeters, with overall disk flatness of ≤0.05 millimeters; all inner hole surfaces are polished and deburred to prevent graphite dust from contaminating sintered workpieces. Special features such as center mounting holes, positioning notches, countersinks, and side mounting holes are machined as a single integrated unit, eliminating the need for secondary assembly.
Optional Anti-Oxidation Coating Extend Service Life: An optional anti-oxidation coating treatment is available; after coating, the discs can withstand oxidation at 1,600°C in an inert atmosphere, extending their service life by 30% to 50% and reducing the customer’s costs associated with frequent replacements. The coating thickness is controlled to within 0.04 millimeters, ensuring that it does not clog the through-holes or impair gas flow efficiency.
Full Customization Without MOQ Restriction: Custom outer diameters range from 100 mm to 1,200 mm, with plate thicknesses ranging from 10 mm to 80 mm. There is no minimum order quantity; we accept single-piece prototypes, small-batch trial production, and long-term high-volume orders. Customers may send samples of used graphite discs or provide CAD drawings; our engineers will complete a 1:1 replica and optimize any structural defects within 24 hours.
One-Stop Matching Graphite Furnace Components Supply: In addition to porous graphite discs, the production line also offers a complete set of furnace-internal components, including graphite supports, graphite sleeves, graphite bolts, graphite heating plates, and graphite boats. Buyers can source all graphite components for high-temperature furnaces in one place, eliminating the need to coordinate with multiple suppliers. For international orders, we provide a complete set of customs clearance documents.
For small-batch powder metallurgy production, laboratory test furnaces, and projects with strict budget constraints, the MSS80 offers better value for money; for large-scale cemented carbide manufacturing plants, multi-layer stacked heavy-duty billets, and long-term continuous sintering operations, the high-density MSS85 (1.90 g/cm³) is the preferred choice, as it provides a longer service life and reduces downtime and replacement costs.
Yes, our factory is equipped with a dedicated high-temperature purification furnace to remove metallic impurities from graphite ingots, reducing ash content to as low as 30 ppm. The purification process adds 4 to 7 business days to the production cycle and is suitable for production scenarios with strict impurity control requirements, such as diamond synthesis and the sintering of high-purity alloys.
No. After the antioxidant coating is applied, workers manually sand and clean any residual coating from the inner walls of all holes, ensuring that the final hole diameter is strictly controlled within the customer’s tolerance range, which does not affect the efficiency of gas flow within the furnace at all.
Material Self-Sufficiency: The parent company operates its own production line for isostatic graphite billets, ensuring consistent raw material quality and competitive factory prices.
Quality Control System: Raw material re-testing, full CNC dimensional inspection, flatness testing, and high-temperature aging simulation tests are conducted to ensure no defective products leave the warehouse.
Agile Customization: We provide free optimization of disc hole layout designs based on customers’ furnace drawings to improve the sintering yield rate on production lines.
Global Service: Products are supplied year-round to Europe, the United States, South Korea, and Southeast Asia, accompanied by a complete set of customs clearance documents, including material test reports, commercial invoices, and packing lists.
Take action now: Click the “Get a Free Sample” button on the right, or send an email to sales@nhdcarbon.com. Our engineers will respond to your technical inquiries within 24 hours.
In addition to porous graphite discs, our production line simultaneously manufactures a full range of furnace-internal components, including graphite supports, graphite sleeves, graphite bolts, graphite heating plates, and graphite boats. Buyers can source all high-temperature furnace graphite components in one place, eliminating the costs associated with coordinating multiple suppliers. We provide complete customs clearance documentation for international orders.
+86-795-4605783 
sales@nhdcarbon.com 
No. 966 of Tiangong South Avenue, High-tech Industrial Park, Fengxin County, Yichun City, Jiangxi Province, China.
