Sinsun Hardware, established in 2006, is a leading manufacturer and global supplier of high-quality fasteners. As Northern China's largest producer of Self-Tapping Screws, we operate from a gigantic 30,000 sqm integrated facility that includes modern production zones, a 12,000 sqm smart warehouse (18,000+ pallet capacity), and multi-language customer support centres. Our yearly supply of over 8,500 containers consistently services key global markets such as the Middle East, Southeast Asia, South America, and Russia.
Our production prowess is driven by German-imported machinery, precision Taiwanese technology, and a dependable staff of trained specialists. We offer over 20,000 SKUs of nails, screws, wires, and rivets, each undergoing 12+ stringent quality checks to assure outstanding polish (Ra ≤ 0.4μm), corrosion resistance (1,000+ hours salt spray), dimensional accuracy (±0.02mm), high strength (1,000+ MPa), and consistent hardness (HRC 28-32).
We specialise in offering unique fastening solutions that are tailored to your specific needs. Our technical team works directly with clients from design to manufacturing, providing support for unusual materials, coatings, dimensions, and performance requirements to ensure that each custom order matches exact specifications.
Acorn nuts, structurally characterized by their domed cap structure, are vital decorative and protective components across multiple engineering verticals. When manufactured from high-grade brass, these components leverage the exceptional properties of copper-zinc alloys to deliver robust corrosion resistance, superior thermal/electrical conductivity, and an aesthetically premium finish. Under international standards such as DIN 1587 (high dome cap nuts) and DIN 917 (low dome cap nuts), precision tolerances are mandatory to prevent thread slippage and internal environmental exposure.
From an engineering standpoint, the closed-end dome structure of a brass acorn nut acts as a physical barrier. It encapsulates the protruding threaded end of a male fastener (bolt or stud). This design yields several distinct mechanical and chemical protections:
Sinsun utilizes certified brass alloys such as H59, H62, and C3604 (Free-Cutting Brass). These compositions contain carefully balanced ratios of copper (57%-63%) and zinc, with trace lead additions to optimize tool life and achieve mirror-smooth finishes during high-speed CNC turning operations.
For applications in moist, saline, or slightly acidic environments, our brass formulations are structured to resist selective leaching (dezincification). This metallurgical stability prevents loss of mechanical shear strength and guarantees the structural longevity of the acorn cap.
Utilizing high-precision multi-spindle automatic lathes and cold-forging systems, we maintain thread class 6H precision for metric standards, and 2B/3B tolerances for imperial threads. Sinsun ensures zero thread misalignment, yielding low friction deployment and consistent clamping force.
The global dominance of Chinese fastener manufacturing is not simply a function of labor cost efficiency; rather, it is the result of complete structural integration, centralized raw material sourcing, and specialized mechanical processing clusters. Sinsun Hardware's facility leverages these localized advantages to provide competitive lead times and cost-to-quality ratios that are hard to match elsewhere.
Sinsun partners directly with regional steel and copper alloy giants, primarily Xingtai Steel. This proximity guarantees access to consistent chemical compositions. In-house processing facilities—featuring four spheroidizing annealing furnaces and high-precision wire-drawing machinery—ensure raw wire stock is processed to precise diameter tolerances before entering the forging step.
By blending high-speed cold-heading machines imported from Germany with Taiwanese automatic thread-rolling units, Sinsun establishes an optimized manufacturing flow. Standard components are formed at rates of up to 250 pieces per minute. This equipment infrastructure is supported by internal tooling shops that produce custom punch dies in-house, cutting sample preparation time from weeks to days.
Located in the industrial heart of Northern China, Sinsun operates with access to deep-water ports (such as Tianjin Xingang) and direct freight networks. Combined with our 12,000 sqm smart warehouse, which maintains an active buffer stock of popular SKUs, we achieve short lead times, dispatching custom orders to sea freight terminals within 15–20 days.
Sinsun began with a singular focus in 2006: to build a factory dedicated to self-tapping screws. This foundational specialization established our core expertise from the ground up. It remains the unwavering commitment behind every screw we manufacture today.
The year 2012 marked a pivotal step for Sinsun with the establishment of our Export Department. From that point forward, our specialized fasteners began reaching customers across the world, expanding our mission beyond domestic borders.
In 2015, Sinsun expanded its control over quality by adding four spheroidizing furnaces for raw material processing and in-house wire drawing capabilities. This strategic upgrade moved our production beyond basic assembly, starting control right from the raw material stage.
Our production capability was enhanced in 2018 with new German multi-station cold heading machines. Concurrently, we grew our product line to include a variety of drill tail screws. This dual development strengthened our specialized manufacturing foundation.
Sinsun's growth in 2021 was defined by two key metrics: reaching 36,000 tons in annual production and fulfilling international orders with over 1,100 export containers. This period underscored our capacity to deliver at scale to a global market.
To ensure timely delivery for our clients, we operate a 1,200-square-meter ready-stock warehouse as of 2023. This facility is dedicated to supporting efficient daily distribution and meeting your routine supply needs.
The addition of four heat treatment lines in 2025 significantly boosts our production capacity. This directly translates to greater consistency in product quality and stronger guarantees for on-schedule delivery, meeting your project needs with confidence.
Maintaining a zero-defect paradigm requires complete mastery over every stage of manufacturing. At Sinsun, we ensure that every batch of brass acorn nuts meets strict quality thresholds prior to packaging and dispatch.
We source premium copper and brass rod coils from reputable suppliers, verifying chemical composition via optical emission spectrometers (OES). This ensures the correct balance of copper, zinc, and trace elements before machining begins.
Our workshop pairs traditional cold heading with high-precision CNC turning centers. This dual approach allows us to produce both high-volume standard runs and low-volume, specialized custom brass dome profiles.
Sinsun operates four specialized heat treatment lines. For our steel products, this guarantees precise core and surface hardness. For our brass lines, controlled stress-relief annealing prevents future stress corrosion cracking in high-torque setups.
We offer diverse finishing options, from clean acid-pickled bright brass to electroplated nickel, chrome, and custom antiqued bronze. Each batch undergoes salt spray testing (up to 1,000+ hours for coated options) to confirm robust corrosion resistance.
Equipped with profile projectors, thread ring and plug gauges, and digital micrometer systems, our QC technicians inspect key features—including pitch diameter, dome height, and thread depth—to an accuracy of ±0.02mm.
Our 12,000 sqm warehouse features modern sorting systems. We offer custom, retail-ready box packaging, 3D design previews for custom boxes, and palletization designed to protect threads during long-distance maritime transport.
Industrial components must meet regional environmental and material compliance codes before entering global markets. Sinsun maintains compliance across key standard frameworks, making us a reliable partner for Tier-1 supply chains.
For electronic, electrical, and automotive assemblies entering the European Union and North America, strict adherence to RoHS (Restriction of Hazardous Substances) and REACH regulations is mandatory. Standard brass alloys often contain trace lead to facilitate machining. Sinsun works with lead-free brass formulations (such as C27450 and C68700) to meet the strict limits of <0.1% lead content where required, providing complete material certification and third-party laboratory verification reports.
We support automotive and defense sector procurement by providing comprehensive PPAP Level 3 documentation. This package includes Failure Mode and Effects Analysis (FMEA), control plans, material test reports (MTR), and dimensional layout analyses, ensuring that changes in manufacturing processes are thoroughly documented and verified.
To support modern lean manufacturing, Sinsun uses its 18,000-pallet smart warehouse to facilitate Just-In-Time (JIT) shipping programs. We establish rolling forecast agreements with clients, manufacturing components in advance and holding safety stock to shield our partners from sudden supply disruptions or shipping delays.
Brass acorn nuts serve critical roles in both functional engineering and decorative architectural systems. Because brass does not rust and provides natural electrical conductivity, these components are highly utilized in several demanding application fields:
Used to secure decorative fittings, instrument panels, and light fixtures on marine vessels. Brass provides excellent resistance to saltwater corrosion compared to standard carbon steels, preventing seized threads in sea air.
In high-voltage cabinets, distribution boxes, and transformer terminals, brass acorn nuts secure busbars and electrical contacts. They provide stable electrical connections while protecting sensitive stud terminals from dirt and moisture.
Applied in high-end plumbing fixtures, mixing valves, and heat exchangers. Brass resists dezincification in potable hot and cold water networks, maintaining structural integrity and preventing leaks.
In staircases, glass balustrades, and structural metalwork, these nuts provide a clean, polished finish. The dome covers sharp thread ends, ensuring safety in public areas while complementing modern design styles.
Used on custom engine valve covers, wheel hubs, and vintage motorcycle assemblies. The high-polish brass surface provides a classic look while offering reliable resistance to vibration and thermal cycles.
With tightening global regulations on lead content in drinking water and consumer products, the industry is shifting toward eco-friendly, lead-free brass formulations. Sinsun is ready to supply these specialized materials to meet compliance needs.
Every month, Sinsun welcomes clients from across the globe for on-site factory audits and tours, demonstrating our production processes and dedication to quality. As a trusted industry partner, we actively participate in major global industrial exhibitions to connect with clients, share manufacturing insights, and showcase our latest fastener developments.
DIN 1587 defines high dome cap nuts, featuring a taller dome and deeper internal thread clearance. This design is ideal for applications where the bolt extends significantly past the joint surface. DIN 917 defines low dome cap nuts, featuring a flatter dome profile. This design is suited for applications with limited vertical clearance where a clean, low-profile finish is required.
Stress corrosion cracking occurs in brass alloys subjected to residual tensile stresses and environmental corrosive agents (such as ammonia). Sinsun prevents this by running controlled stress-relief annealing cycles after high-speed forging or thread rolling. This process relieves internal material stresses without reducing the hardness or strength of the threads.
Yes. To comply with environmental standards like the US Safe Drinking Water Act and EU RoHS regulations, we offer lead-free brass options, including C27450 and C68700. These materials limit lead content to below 0.1% while maintaining good machinability and corrosion resistance.
We typically machine metric threads to class 6H standards and imperial threads to 2B or 3B tolerances. By checking our production output with precision Go/No-Go thread plug gauges, we ensure reliable fitment and consistent torque response for every batch.
Beyond our standard clean, acid-pickled bright finish, we offer nickel plating, chrome plating, silver plating, copper plating, and chemically blackened finishes. We can also apply antiqued finishes to match architectural decorative themes.
For standard metric sizes, our MOQs depend on tool setup requirements, typically starting around 10,000 pieces per size. Custom sizes requiring unique die profiles carry a lead time of 25 to 30 days, including die creation, sample verification, and production runs.
