Carbon Carbon Studs

As a manufacturer of carbon carbon composite materials with 18 years of production history, JUN TENG operates a complete in-house manufacturing chain—from 3D preform weaving and impregnation carbonization to 2800°C graphitization and precision CNC machining. Our factory supplies Carbon Carbon Studs as long-core fasteners for high-temperature vacuum thermal fields, used with matching C/C nuts and washers to secure large graphite components in photovoltaic single-crystal furnaces, semiconductor CVD chambers, and vacuum heat treatment systems.

What sets our factory's studs apart from resin-based carbon fiber bolts (decompose above 200°C), graphite bolts (powder and crack under thermal cycling), molybdenum bolts (soften above 1650°C), or stainless steel bolts (fail below 900°C) is this: our C/C studs maintain thread integrity and clamping force at 2200°C in inert atmospheres. As a direct manufacturer, we control every step of production—achieving density of 1.64-1.73g/cm³, ash content below 550ppm, thermal expansion matching graphite components (0.85-1.35×10⁻⁶/K), and thermal shock resistance exceeding 1300 cycles without cracking—the highest purity and thermal shock resistance in our supplier product line.

Our factory supplies photovoltaic and semiconductor equipment manufacturers worldwide. We offer standard sizes M3-M30, lengths 10mm-600mm, full-thread or partial-thread configurations, and custom stepped designs. As a one-stop supplier, we also provide matching C/C nuts and washers for complete fastening assemblies. Every batch is tested by CNAS-accredited third-party laboratories, with full test reports included. Factory-direct procurement with 48-hour delivery on standard stock sizes.

Comparison Table of Core Technical Parameters

Core advantages and selling points of the product

1. High temperature resistance without creep, long-lasting and stable fastening strength

It can be used stably in a vacuum/inert environment at 2200℃for a long time, without problems such as elongation, bending, and wire slippage caused by high-temperature creep like metal bolts, avoiding frequent shutdown and maintenance due to fastener failure, and greatly improving the continuous production efficiency of equipment.

2. Low thermal expansion coefficient, strong adaptability to graphite thermal field

The thermal expansion coefficient is close to that of graphite sheet and carbon carbon composite components, and there is no significant change in the thread clearance during repeated temperature rise and fall processes, effectively preventing assembly looseness and thermal field displacement problems.

3. High purity all carbon material, clean and pure furnace with zero pollution

The product does not contain any metal components, and there is no volatile impurity precipitation in ultra-high temperature environments. It will not contaminate silicon wafers, semiconductor wafers, and high-purity insulation materials, significantly reducing the scrap rate of photovoltaic and semiconductor production lines.

4. Lightweight and heat-resistant, with a longer service life

The self weight is only 1/6 of the molybdenum screw, effectively reducing the overall load on the furnace heat field and equipment lifting structure; After thousands of cycles of alternating hot and cold, it does not crack or layer, and its service life is 3-6 times that of metal high-temperature bolts.

5. Multi specification customization, optional anti-oxidation coating

Support customization of full tooth, half tooth, stepped, elongated, and shortened irregular bolts; Under aerobic conditions, customized silicon carbide anti-oxidation coatings can be applied to expand usage scenarios beyond vacuum furnaces. Perfectly compatible with Junteng's self-produced carbon nuts and washers, achieving a complete set of fastening assembly.

Complete production process flow

Junteng's Carbon Carbon Studs adopt closed-loop integrated independent production, with 12 strict quality inspection nodes set throughout the entire process:

1. Select 12K continuous carbon fiber woven three-dimensional integrated preform to ensure fiber continuity without delamination or fracture;

2. Multiple vacuum high-pressure asphalt impregnations are used to fill the internal pores and improve the density of the green body;

3. Segmented carbonization treatment at 1000℃to solidify the carbon matrix structure;

4.2800℃ultra-high temperature graphitization purification, removing trace ash content and reducing impurity precipitation;

5. Five axis CNC machine tool with dedicated diamond cutting tools for precision threading, with full and burr free tooth profile and no broken edges;

6. Surface polishing, full-size inspection, and spray SiC anti-oxidation coating as needed; The finished products are classified and stored after manual re inspection of appearance and tolerance.

Application scenarios and scope of use

1. Photovoltaic new energy industry: Long distance fixed connections of graphite support frames, insulation pressure plates, and thermal field overall frames inside single crystal furnaces and polycrystalline ingot furnaces;

2. Semiconductor precision equipment: fastening large graphite components inside CVD deposition furnaces, vacuum diffusion furnaces, and high-purity annealing furnaces to prevent metal contamination of chips;

3. Industrial high-temperature heat treatment: Vacuum sintering furnace, carbonization furnace, graphitization furnace fixtures, large mold long-distance connectors, replacing high priced molybdenum screws to reduce consumable costs;

4. Aerospace and laboratory research: Long term fastening accessories for high-temperature tube furnaces, thermal protection test benches, and vacuum thermal simulation test equipment.

Standard Usage Instructions

1. Clean the dust and debris inside the threads before assembly, apply a thin layer of high-purity graphite lubricant powder to reduce thread friction loss;

2. Use a torque wrench to lock evenly, and it is strictly prohibited to use pneumatic impact tools to prevent brittle carbon material threads from breaking;

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

4. When assembling long components at multiple points, they should be locked symmetrically in batches to avoid uneven force that may cause bolt breakage; Paired with Junteng's original carbon nuts and washers, it maximizes the service life 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 hard objects; Uncoated bolts cannot be used in air environments above 800℃for a long time, as they will continue to oxidize and wear out; Avoid frequent disassembly and assembly, as repeated friction can wear down the thread profile and reduce fastening accuracy; Finished products are stored in a dry and ventilated warehouse, and moisture absorption can cause cracking during high-temperature use; It is prohibited to mix and assemble with iron, molybdenum, and tungsten metal bolts, as electrochemical reactions may occur at high temperatures and produce impurities that can contaminate the furnace.

Customer Core Concerns and Targeted Solutions Table

Authoritative qualifications and testing certification

Our factory holds ISO9001 international quality management system certification and enterprise safety production standardization certification; Carbon Carbon Studs is equipped with a complete set of CNAS testing reports, covering high temperature resistance, thermal expansion coefficient, ash content, and thermal shock resistance testing items.

The enterprise has designated qualified suppliers for multiple listed photovoltaic and semiconductor companies, and all supplier qualification documents can be provided for customer verification. Each batch of products comes with an independent factory quality inspection form, and the raw material batches and processing procedures can be traced throughout the entire process to prevent the mixing and shipment of defective products from the root.

Frequently Asked Questions

Q1: What is the difference between Carbon Carbon Studs and regular graphite studs? 

A: The internal structure of graphite screws is loose, with low strength, and is prone to fracture and powder loss at high temperatures, resulting in a short service life; Junteng carbon screw is a fiber-reinforced composite structure with high density and good strength. It does not shed powder in ultra-high temperature environments and has a service life more than 5 times that of graphite screw. The two are not interchangeable.

Q2: Can I purchase bolts separately and use them with nuts from other manufacturers?  

A: Support separate procurement of bolts, but Junteng's matching nuts and bolts adopt a unified thread tolerance design, which improves assembly fit and overall stability. It is recommended to purchase the entire set.

Q3: What lengths and thread specifications can be customized?  

A: The thread diameter covers M3-M30, with a single piece length of 10mm-600mm. It supports customization of half tooth, full tooth, and stepped transition shapes, and is suitable for various large-scale thermal field renovation needs.

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

A: Stable vacuum inert environment can be used for 12-26 months; SiC anti-oxidation coating screws can be used for 6-11 months in aerobic high-temperature environments with extremely low wear and tear.

Transaction protection and full cycle after-sales service

Transaction Guarantee

18 years of direct operation from the source manufacturer, long-term stable batch factory preferential prices; Support corporate signing, issuing value-added tax invoices, and stamping bidding qualifications; Free sample testing is provided, and if the sample performance does not meet the standards, a full refund will be issued; Large scale orders can be signed with formal quality assurance agreements, and if the size or performance is not qualified, it will be returned or replaced; Welcome customers to visit the factory for on-site inspection; Standard inventory products can be shipped quickly without delaying customer production lines.

After-sales service

Professional high-temperature composite material engineers provide one-on-one free working condition selection plans and provide technical data on the assembly torque of bolts, nuts, and washers; Free replacement for non-human damage during the warranty period; Real time synchronization of processing progress for customized orders; Lifetime free consultation on high-temperature thermal field materials and equipment modification technology; Regular technical follow-up visits to long-term cooperative customers, synchronized with the upgrade plan for new composite materials. Welcome new and old customers to inquire about samples and bulk cooperative procurement.