Carbon Carbon Washers

JUN TENG has been manufacturing carbon carbon composite materials for 18 years, operating an integrated production line covering 3D preform weaving, impregnation, 2800°C graphitization, and precision CNC machining. Our Carbon Carbon Washers are specifically designed for high-temperature fastening systems—used alongside C/C bolts, screws, and nuts to distribute load, prevent loosening, and seal against contamination in photovoltaic, semiconductor, and vacuum heat treatment furnaces.

Unlike graphite washers that powder and flake at high temperatures, molybdenum washers that soften and deform above 1600°C, or stainless steel washers that fail below 900°C, our carbon carbon washers maintain structural integrity at 2200°C in inert atmospheres. The 3D carbon fiber preform structure delivers density of 1.63-1.72g/cm³, ash content below 580ppm, thermal expansion coefficient matching graphite components, and thermal shock resistance exceeding 1200 cycles without cracking.

Every batch is tested by CNAS-accredited third-party laboratories. We supply leading manufacturers in photovoltaic, semiconductor, and aerospace high-temperature sectors. Standard sizes M2-M50 in stock, custom thickness and countersunk styles available. Matching C/C bolts, screws, and nuts offered for complete one-stop fastening solutions. Full test reports, ISO9001, CE certification included.

Core physical and chemical technical parameters

Core advantages and selling points of the product

1. Ultra high temperature resistance, no creep deformation at high temperatures, inert atmosphere at 2200℃, long-term stable use, no softening, thinning, or collapse of metal gaskets at high temperatures, long-lasting and stable fastening strength, greatly reducing the frequency of equipment shutdown and replacement.

2. Low thermal expansion coefficient, perfectly matched with graphite components. The thermal expansion value is close to that of graphite furnace and carbon plate. The gasket fits tightly during the entire temperature rise and fall process, preventing high temperature thread loosening and pressure plate displacement. It is suitable for 24-hour continuous production equipment.

3. High purity metal free, eliminating furnace cleanliness pollution without any metal components, high temperature without volatilization, no heavy metal impurities precipitation, will not pollute silicon wafers, wafers, high-purity insulation layers, directly improving the yield of photovoltaic and semiconductor products.

4. Lightweight and highly resistant to thermal shock, with repeated temperature cycling and no cracking. The self weight is only 1/6 of the molybdenum pad, reducing the overall load-bearing capacity of the thermal field; Thousands of cold and hot cycles without cracking or delamination, with a service life far exceeding that of traditional metal gaskets.

5. Strong compatibility and support for anti-oxidation customization to perfectly match our factory's full specification carbon screws. We can process countersunk, irregular, thickened and ultra-thin styles as needed; Under aerobic conditions, SiC anti-oxidation coating can be used to expand the application scenarios of high temperature air.

Complete production process introduction

JUNTENG's Carbon Carbon Washers adopt an independent closed-loop integrated production process, with 12 quality control nodes throughout the entire process to ensure quality.

The first step is to use 12K continuous carbon fiber to weave three-dimensional prefabricated blanks, ensuring that the fibers are continuous and not layered;

The second step involves multiple vacuum high-pressure asphalt impregnation to fill the pores and improve the density of the green body;

Step 3: 1000℃segmented low-temperature carbonization and solidification of carbon matrix;

Step 4: 2800℃ultra-high temperature graphitization purification to remove trace ash impurities;

The fifth step is CNC precision grinding of five axis diamond cutting tools, with strict control over the parallelism of the washer plane and the outer diameter tolerance of the inner hole;

Finally, the final inspection and polishing are carried out, and SiC anti-oxidation coating is sprayed as needed. The finished product is manually inspected for its full size appearance before being stored.

Application scenarios and practical uses

1. Photovoltaic new energy: single crystal/polycrystalline ingot furnace graphite insulation module pressing plate, thermal field fixture fastening gasket, matched with carbon carbon screws for complete use;

2. Semiconductor precision equipment: CVD deposition furnace, vacuum diffusion furnace, high-purity annealing furnace internal sealing gasket, strict control of metal impurity pollution;

3. Industrial high-temperature heat treatment: fixing fixtures for vacuum sintering furnaces, carbonization furnaces, and graphitization furnaces to replace expensive molybdenum gaskets and reduce consumable costs;

4. Aerospace research: High temperature tube experimental furnace, thermal protection testing equipment, vacuum high-temperature testing machine fastening and sealing accessories.

Standardized usage instructions

1. Clean the dust inside and outside the gasket holes before assembly, and thin coat high-purity graphite lubricating powder to reduce thread friction loss;

2. Use a torque wrench to tighten evenly, and prohibit strong compression from pneumatic air cannons to prevent gasket edge breakage;

3. Uncoated carbon carbon gaskets are only suitable for use in inert environments such as vacuum, nitrogen, and argon; SiC coating must be selected for aerobic high-temperature conditions;

4. Multi component symmetrical segmented locking to avoid gasket breakage caused by unilateral force; The use of our factory's carbon screws can maximize the lifespan of the entire set of fasteners.

Precautions for use

Carbon carbon composite materials are brittle materials and are strictly prohibited from being hit by heavy objects, falling from heights, or scratched by sharp hard objects; Products without anti-oxidation coating cannot work in air environments above 800℃for a long time, as it will rapidly oxidize and cause damage; It is not recommended to disassemble and dismantle frequently, as repeated squeezing can cause wear on the gasket surface; Finished products should be stored in a dry and ventilated warehouse, as prolonged exposure to moisture and water absorption can cause cracking during high-temperature use; Do not mix or stack with iron, molybdenum, or tungsten metal gaskets, as they can easily produce electrochemical impurities and contaminate the furnace at high temperatures.

Customer Core Concerns and Targeted Solutions Table

Authoritative qualifications and testing certification

The factory holds ISO9001 international quality management system certification and safety production standardization certification. Carbon Carbon Washers products have a complete set of testing reports issued by CNAS accredited laboratories for high temperature resistance, thermal expansion, purity, and thermal shock resistance; The enterprise is a designated qualified supplier for multiple domestic photovoltaic and semiconductor listed companies, and its cooperation qualifications and supplier certification documents can be provided for external verification; Each batch of products comes with an independent factory quality inspection form, and the production process and raw material batch can be traced throughout the entire process to prevent substandard products from being sold as good.

Frequently Asked Questions (FAQ)

Q1: What is the difference between carbon carbon gaskets and ordinary graphite gaskets?  

A: Ordinary graphite gaskets have a loose texture and are prone to powdering, falling off, and polluting the furnace at high temperatures. They also have low strength and are prone to cracking; JUNTENG carbon carbon gasket is a carbon fiber composite structure, dense and high-strength, with no powder shedding at high temperatures. Its service life is more than 5 times that of graphite gasket, and the two are irreplaceable.  

Q2: Can washers be purchased separately and used with screws from other suppliers? 

A: We support separate procurement, but our factory's carbon washers are optimized for matching with JUNTENG carbon screws in terms of size and tolerance, resulting in better overall assembly stability and service life. We recommend purchasing the entire set.  

Q3: What is the minimum/maximum specification that can be achieved? Does it support customized non-standard drawings?  

A: Full specification coverage with inner diameter of 2mm~50mm, thickened, ultra-thin, countersunk, and irregular gaskets can be customized according to drawings, and CNC machining is suitable for various equipment modification needs.  

Q4: How long is the service life under normal operating conditions?  

A: The vacuum inert stable working condition can be used for 12-24 months; SiC coating can be used normally under aerobic conditions for 6-10 months with extremely low losses.

Transaction guarantee and full process after-sales service

Transaction Guarantee

18 years of direct operation by the source factory without any intermediary markup, with long-term stable bulk factory prices; Support corporate contract signing, value-added tax invoicing, and bidding qualification stamping; Free sample testing, full refund for samples that do not meet performance standards; Large scale orders can be signed with a quality assurance agreement. If the size or physical and chemical properties are not qualified, we offer a return or replacement policy. Customers are welcome to visit our factory for on-site inspection; Standard specifications are readily available in stock, ensuring fast delivery without delaying production on the production line.

After-sales service

Professional high-temperature material engineers provide one-on-one free working condition selection and offer a complete set of screw and washer assembly torque process solutions; Free replacement for non-human damage during the warranty period; Real time synchronization of processing progress for customized orders; Lifetime free provision of high-temperature material technology consultation and equipment thermal field transformation adaptation solutions; Regular technical follow-up visits for long-term cooperative customers, synchronized optimization and upgrading plans for new materials, welcome new and old customers to inquire about samples and bulk purchases.