Nickel Alloy Fasteners
Nickel based alloys and special stainless steels can well meet the requirements of chemicial corrosion, high temperatures and strict pressure. Fasteners made of these materials are widely used in industries such as petrochemicals, food manufacturing, semiconductors, chemical processing and electronic equipment. More info
Mill cert and inspection report provided every shipment.
Advanced Metallurgy for Extreme Environments
In industries where equipment failure is not an option, standard fasteners often succumb to rapid corrosion or fatigue. Screwtool addresses this gap by specializing in the nickel alloy fastener category and dual-phase steel solutions. Our product range is engineered for sectors like offshore oil and gas, chemical processing, and desalination, where components face constant exposure to chlorides, acids, and high pressures. Unlike commodity grade 304 or 316 stainless steel, our inventory features duplex 2205 (UNS S31803/S32205) and special stainless steel grades that offer superior pitting resistance. By integrating these advanced materials into our supply chain, we provide maintenance teams and project engineers with hardware that significantly extends the service life of critical infrastructure, reducing the frequency of costly shutdowns for maintenance repairs.
Microstructure and Mechanical Superiority
The defining technical characteristic of our duplex fastener offerings lies in their microscopic grain structure. Consisting of a balanced mix of roughly 50% ferrite and 50% austenite, these fasteners deliver a unique combination of toughness and strength. Specifically, duplex 2205 provides a yield strength approximately double that of conventional austenitic stainless steels. For applications requiring even higher performance, we manufacture super duplex fastener components using grade 2507 (UNS S32750). This material contains higher levels of chromium, molybdenum, and nitrogen, elevating its Pitting Resistance Equivalent Number (PREN) above 40. This metallurgical advantage ensures that our bolts and nuts remain structurally sound even when submerged in warm seawater or exposed to aggressive chemical media that would cause stress corrosion cracking in lesser alloys.
Custom Fabrication and Quality Assurance
While we maintain stock of standard sizes, Screwtool excels in the bespoke manufacturing of special stainless steel and nickel-based alloy fasteners. Whether your project requires Monel 400, Inconel 625, or Hastelloy C-276, our production facilities in Lianyungang can accommodate specific drawing requirements. We utilize both cold heading for smaller diameters and hot forging for large-diameter bolts (up to M100) to ensure the grain flow of the metal aligns with the fastener geometry, maximizing strength. Every nickel alloy fastener we produce is subject to rigorous quality control protocols. This ensures that the thread profile, dimensional tolerances, and surface finish meet strict ISO and ASTM standards, preventing issues like galling during installation—a frequent challenge when working with high-performance alloys.
Advantages
Unmatched Corrosion Resistance Capabilities
The primary operational advantage of switching to a super duplex fastener is its immunity to localized corrosion mechanisms. In marine and chemical environments, chloride ions attack the passive layer of standard steel, leading to pitting and crevice corrosion. Our super duplex 2507 fasteners are chemically engineered to resist this attack. The high molybdenum content acts as a stabilizer, allowing the fasteners to function reliably in environments such as flue gas desulfurization units or subsea manifolds. For engineers, this translates to “fit and forget” reliability. By selecting the appropriate nickel alloy fastener or duplex grade, you eliminate the need for secondary protective coatings like galvanization or PTFE, which can wear off over time, thereby ensuring the structural integrity of the joint for the asset’s entire design life.
High Strength-to-Weight Efficiency
The mechanical properties of duplex 2205 allow for significant design optimization. Because these fasteners possess yield strengths ranging from 450 to 550 MPa (compared to ~210 MPa for 316L), design engineers can often downsize the fastener diameter or reduce the total number of bolts required for a flange connection without compromising the clamping load. This reduction in weight is particularly valuable for offshore platforms and floating production storage and offloading (FPSO) units, where every kilogram added to the topside structure impacts stability and cost. Furthermore, the high fatigue strength of our special stainless steel bolts makes them ideal for dynamic applications involving vibration, such as pump mountings and turbine housings, where cyclic loading typically leads to fatigue failure in weaker materials.
Temperature and Chemical Stability
Our portfolio extends beyond simple corrosion resistance to address temperature extremes. While duplex fastener grades are excellent for moderate temperatures, our specific nickel alloy fastener options (like Inconel and Nimonic) are designed to retain their mechanical properties at temperatures exceeding 700°C or in cryogenic conditions. This thermal stability ensures that the fastener does not suffer from creep or brittle fracture during operation. Additionally, in chemical processing involving reducing acids (like hydrochloric or sulfuric acid), nickel alloys offer resistance that stainless steel cannot match. By sourcing from Screwtool, procurement teams gain access to a spectrum of materials that can be precisely matched to the chemical composition of the process fluid, ensuring safety and compliance with environmental regulations regarding leakage and containment.
Use Scenarios
Desalination Plant Infrastructure
A Plant Engineer managing a Reverse Osmosis (RO) desalination facility faces constant challenges with saltwater corrosion. The high-pressure pumps and piping systems handle brine with extremely high chloride concentrations. The engineer specifies Screwtool’s super duplex 2507 stud bolts and heavy hex nuts for all high-pressure flange connections. The choice of super duplex fastener is critical because the operational temperature and chloride content would cause standard 316L bolts to fail within months due to pitting. By using our high-PREN fasteners, the facility avoids dangerous high-pressure leaks and eliminates the need for frequent, expensive shutdowns to replace corroded hardware, ensuring a continuous supply of potable water.
Offshore Oil & Gas Platforms
In the construction of an offshore drilling rig, a Structural Designer must ensure that the equipment bolted to the deck can withstand the harsh marine atmosphere and wave impact. The designer selects duplex 2205 hexagon head bolts for securing cable trays, handrails, and non-subsea structural elements. The high yield strength of the duplex fastener allows for smaller, lighter bolted joints, which helps in weight control for the platform. For the subsea “Christmas tree” valves and manifolds, the designer escalates the specification to nickel alloy fastener grades like Inconel 625 to withstand the extreme hydrostatic pressure and corrosive sour gas (H2S) environments found at the wellhead, ensuring long-term safety without diver intervention.
Chemical Tank Farm Construction
A Procurement Manager for a new chemical storage facility needs to source fasteners for tanks holding various aggressive acids. The project involves flanges connecting pipes carrying acetic acid and sulfuric acid. Standard steel is unsuitable, and the manager consults Screwtool for a solution. For the acetic acid lines, we supply special stainless steel bolts (like 904L or Duplex), while for the more aggressive sulfuric acid tanks, we provide Hastelloy C-276 fasteners. The manager utilizes our ability to supply nickel alloy fastener products in small batch quantities (low MOQ) for these specific critical joints. This precise material selection prevents catastrophic tank failures and environmental spills, ensuring the facility meets strict EPA safety standards.
About Us
Shanghai Screwtool Industrial Co., Ltd. is a premier manufacturer and supplier of industrial fasteners, established in 2011 as a subsidiary of the Victor Screw Group. We specialize in bridging the gap between China’s advanced manufacturing capabilities and the rigorous demands of the global market. While we produce standard fasteners, our core competency lies in high-performance materials, including nickel alloy fastener solutions, duplex fastener products, and special stainless steel. Our facilities in Shanghai and Lianyungang are equipped with advanced cold heading and hot forging machinery, enabling us to produce complex OEM parts to precise customer drawings. We are ISO 9001 certified and committed to full transparency, providing Mill Test Certificates (MTC) and inspection reports with every shipment. Whether you require a single carton of specialized alloy bolts or a full container of standard parts, our flexible supply chain ensures timely delivery and consistent quality for industries ranging from marine engineering to petrochemical processing.
Call to Action
Contact our team today to get a quote for your super duplex fastener and nickel alloy requirements!
FAQ
What is the Minimum Order Quantity (MOQ) for nickel alloy fasteners?
For standard items in stock, our MOQ is flexible, typically starting at 1 carton. For custom nickel alloy fastener orders, the MOQ depends on the size and weight; for example, it might be 30,000 pcs for M6 sizes or 5,000 pcs for M10 sizes.
Can I get samples of Super Duplex 2507 bolts before placing a bulk order?
Yes, if we have existing molds or stock, we can provide free samples of super duplex 2507 fasteners for quality checking, with the customer covering only the freight cost. For custom items, a mold fee and sample fee may apply.
What is the typical lead time for these special alloy products?
If the items are in stock, we ship within 7-10 days. For mass production of custom duplex fastener orders, the lead time is generally 25-35 days, while sample production typically takes 10-15 days.
Do you provide material certification for these high-value alloys?
Absolutely. We provide full Mill Test Certificates (MTC), inspection reports, and RoHS documents with every shipment to verify the chemical composition and mechanical properties of the special stainless steel or nickel alloys.
Can you manufacture fasteners to my specific drawings (OEM)?
Yes, we fully support OEM and ODM services. We can manufacture duplex 2205 and other alloy fasteners based on your technical drawings or samples, catering to non-standard dimensions and unique head styles.
