Premium Molybdenum Screws – 99.95% Pure Fasteners for Extreme Applications

We supply molybdenum screws with purity ≥99.95% for vacuum-furnace, semiconductor and laboratory assemblies. Selection depends on the finished-part drawing and the actual atmosphere, temperature and mechanical loading.

For a quotation, send the thread designation and pitch, head type, overall length and threaded length, quantity, tolerances and mating-part details. Include the operating and peak temperatures, hold time, thermal cycling, vacuum level or gas atmosphere, and the required material and inspection documents.

🔧 What Are Molybdenum Screws?

Molybdenum screws are threaded fasteners made from a refractory metal with a high melting point and low thermal expansion. These material characteristics are useful when assessing vacuum and controlled-atmosphere assemblies; the complete joint still requires application-specific evaluation.

The material melting point is not a screw service-temperature rating. High-temperature suitability depends on atmosphere, exposure time, load and material condition. Molybdenum can oxidize in hot air and other oxidizing environments; vacuum or protective-gas conditions must be specified. Screw preload, engagement and any sealing function require a separate joint-design assessment.

🏭 Manufacturing Process

Our molybdenum screws are manufactured through a rigorous process to ensure purity and dimensional accuracy:

Powder Metallurgy: High-purity molybdenum powder is sintered into dense billets under vacuum.
Hot and Cold Rolling: Billets are formed into rods through controlled rolling processes.
Precision CNC Machining: Threads and screw heads are machined using multi-axis lathes.
Thread Machining: State the external thread designation, pitch and tolerance class on the screw drawing. Specify mating internal-thread requirements separately; the machining route and inspection method are confirmed for the agreed drawing.
Deburring & Surface Finish: Define the required finish and cleanliness on the drawing. Any coating or surface treatment needs a specified process and review against the operating atmosphere; a finish name alone does not establish oxidation or corrosion protection.

📐 Technical Specifications

Parameter	Description
Material	Molybdenum ≥ 99.95%
Standards	Raw material: ASTM B387/B387M where specified. Metric threads: DIN 13 / ISO 261 / ISO 965 as agreed on the finished-part drawing. Confirm the governing standard for UNC/UNF threads separately.
Available Threads	M2–M12, UNC/UNF (e.g., ¼-20, #8-32), custom
Length Range	5 mm to 100 mm (customizable)
Head Types	Hex head, socket head cap, slotted, pan, custom designs
Surface Finish	As-machined, polished, or black oxide
Hardness	HV 250–300
Density	10.2 g/cm³
Melting Point	2620°C
Thermal Conductivity	~138 W/m·K
Electrical Resistivity	5.3 µΩ·cm

Drawing confirmation: Specify the screw external-thread tolerance and the mating internal-thread requirement separately, together with the required engagement. Special dimensions, thread classes and listed surface finishes, including any black-oxide treatment, are subject to process and application review. Confirm the agreed inspection criteria before ordering.

🧪 Key Properties & Benefits

✅ High-Temperature Selection: Review temperature, atmosphere, load and exposure time for the specific assembly; this page does not assign a universal maximum operating temperature.
✅ Low Vapor Pressure: Relevant to vacuum use, with final suitability depending on surface cleanliness, outgassing requirements and operating conditions.
✅ Chemical Compatibility: Assess the actual medium, concentration, temperature and oxidizing conditions. Molybdenum is not inert to all acids, alkalis or molten metals.
✅ Dimensional Considerations: Low thermal expansion can help control dimensional change; joint loading and repeated heating and cooling still require assessment.
✅ Drawing Review: Confirm machining feasibility for the requested head geometry, thread, dimensions and tolerance requirements.
🔗 Learn more about molybdenum’s mechanical and thermal behavior on Matmatch.

🔬 Applications of Molybdenum Screws

Typical application areas are listed below. These are selection contexts, not blanket approvals for a specific process, temperature or regulated service; confirm the requirements of the actual equipment before ordering.

Vacuum Furnaces & Hot Zones: For structural assembly inside heating chambers
Semiconductor Equipment: Including wafer etching, sputtering, and deposition tools
Sapphire & Crystal Growth: High-purity, thermally-stable hardware for GaAs, Si, or sapphire crystal pulling
Aerospace: As part of engine shielding or high-temperature insulation clamps
Nuclear & Chemical Reactors: Any such use requires review of the actual process chemistry, operating conditions and project-specific qualification requirements.
University & National Labs: Vacuum assemblies, sample holders, and chamber seals

📦 Packaging & Shipping

To protect the quality and purity of molybdenum screws, we use the following packaging:

Vacuum-sealed or anti-static PE bags
Foam trays or sponge inserts for shock absorption
Export-grade outer cartons
Optional desiccants for moisture control

Confirm the delivery destination, shipping method and required documents during quotation. Specify which of the following are needed so their availability and applicability can be confirmed for the order:

Commercial invoice
Packing list
Certificate of Origin
Material Test Report (MTR)
Safety data and any required RoHS/REACH declarations or supporting documentation

Quotation and Documentation

Provide your drawing and operating requirements so the proposed supply scope, inspection plan, packaging and lead time can be reviewed. If your purchasing process requires a quality-system certificate, supplier qualification records or material traceability, request the relevant documents and confirm their scope and validity before ordering.

Non-standard threads, miniature heads and special tolerances require a drawing review before supply is confirmed.

Material References and Finished-Screw Requirements

ASTM B387/B387M covers molybdenum and molybdenum-alloy bar, rod and wire. When it is specified for the starting material, confirm the applicable material grade, condition and required test records. This material standard alone does not establish the dimensions, threads or service performance of a finished screw.

State the finished-screw requirements separately: head geometry, thread designation and pitch, external-thread tolerance, mating internal-thread requirement, lengths, surface condition and inspection criteria. Identify the applicable metric or UNC/UNF thread specification and edition on the purchase drawing. Confirm any additional compliance requirements during quotation.

If your project requires starting stock rather than finished fasteners, see our 99.95% molybdenum rod and specify the required stock dimensions and material documentation.

📞 Contact Us

📧 Email: sales@niticu.com
📞 Phone / WeChat / WhatsApp: +86 13335373172
🏭 Factory Address: Baotai Road Industrial Park, High-tech Zone, Baoji City, Shaanxi Province, China
🌐 Website: https://niticu.com

Molybdenum Screws

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