Explore our industrial-grade structural screws, fasteners, and heavy-duty fixing systems designed for critical engineering applications.
Sinsun Hardware: Driving global assembly reliability with Taiwanese tech and German machinery since 2006.
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. We guarantee reliable and rapid lead times for both standard and special orders by using our integrated facility, optimised inventory, and effective planning. Sinsun Hardware is your strategic partner, committed to delivering quality, innovation, and on-time performance worldwide.
A comprehensive analysis of design, performance, and metallurgical dynamics in high-stress applications.
Crown cap nuts (often called acorn nuts or dome nuts) feature a closed dome that encases the protruding bolt thread. This acts as a physical barrier against moisture, corrosive fluids, and physical impacts, stopping galvanic corrosion and mechanical thread stripping.
Sinsun Hardware manufactures crown cap nuts to global industrial standards: DIN 1587 (hexagonal domed cap nuts, high pattern), DIN 986 (prevailing torque type with non-metallic insert), and ASME B18.2.2. Our precision tooling guarantees a thread tolerance of 6H/6g.
Available in premium carbon steels (Class 6, 8, and 10), marine-grade A2/A4 stainless steels, and brass. Using clean materials prevents hydrogen embrittlement and ensures high fatigue limits in heavy equipment applications.
In standard low-cost manufacturing, cap nuts are often made by welding a stamped sheet metal dome onto a standard hex nut. Under high-vibration applications (such as automotive suspensions or vibrating sorting screens), these welded seams can split, allowing moisture to gather inside and causing hidden thread failure. At Sinsun Hardware, we construct our crown cap nuts using one-piece solid cold-forming technology. The hex base and the protective dome are formed out of a single steel blank. This keeps the grain structure continuous, eliminating weak points and offering superior fatigue resistance.
How Crown Cap Nuts solve complex engineering challenges across industrial sectors worldwide.
In high-vibration equipment, exposed threads can catch debris and experience thread shear. The domed cap design distributes local clamp loads and protects standard fasteners, lowering equipment downtime in global mining and agricultural sectors.
In food processing, pharmaceutical, and chemical cleanrooms, exposed threads can harbor bacteria. Cap nuts have a smooth, curved shape that is easy to sanitize, preventing biological buildup and helping plants meet strict food safety standards.
High salinity accelerates electrochemical corrosion. Our cap nuts, protected by 1,000+ hour salt spray coatings or A4 marine-grade stainless steel, protect the threaded end of bolts from saltwater contact, extending the lifespan of marine equipment and bridges.
Different markets have specific regulatory requirements. Sinsun Hardware offers custom coating solutions to meet these local needs. For instance, in the European Union, we supply RoHS and REACH-compliant Cr3+ (Trivalent Chromium) passivated zinc plating, which delivers excellent corrosion protection without the environmental impact of traditional hexavalent chromium. For heavy industries in North America and Russia, we provide thick, mechanical zinc-coatings that withstand sub-zero structural installations without cracking.
Sinsun Hardware controls every step of production. We source high-grade steel from Xingtai Steel, draw the wire in-house, and use advanced heat treatment to ensure consistent mechanical performance.
We start with premium steel coil stock from XING TAI Steel. We run spheroidizing annealing and wire drawing in-house to achieve a uniform microstructure, preventing micro-cracking during cold heading.
Multi-station cold heading machines from Germany and Taiwan shape the hex base and dome in a single run. This process maintains tight tolerances (±0.02mm) and delivers a smooth surface finish (Ra ≤ 0.4μm).
Our four continuous heat treatment lines precisely manage carbon levels, quenching, and tempering. This achieves an optimal hardness range of HRC 28-32 and a tensile strength of 1,000+ MPa.
Explore our journey of global growth, technical innovation, and capacity expansion since 2006.
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, directing our commitment to high-quality fastener manufacturing.
The year 2012 marked a pivotal step for Sinsun with the establishment of our Export Department. From that point forward, our specialized self-tapping screws began reaching customers across the world, expanding our mission beyond borders.
In 2015, Sinsun expanded its quality control by adding four spheroidizing furnaces for raw material processing and in-house wire drawing capabilities. This strategic upgrade allowed us to monitor quality starting directly from the raw material steel coil.
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, strengthening our 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, proving our capacity to deliver at scale.
To ensure rapid deliveries for our clients, we opened a 1,200-square-meter ready-stock warehouse. This facility is dedicated to supporting efficient daily distribution and meeting 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.
How we integrate automation, smart tracking, and sustainable metallurgy to build next-generation fasteners.
We are investing in green coatings, such as zinc-flake processes, that provide 1,500+ hours of salt spray resistance without using harmful acids or heavy metals, helping projects meet global eco-directives.
By upgrading our automated optical sorting machines, we target zero-defect manufacturing. This allows us to supply high-precision cap nuts that work seamlessly in automated robotic assembly lines.
We are developing new Class 12.9 cap nuts using micro-alloyed boron steels, designed to maintain clamping force in high-load industrial structures.
Every month, we welcome international clients to our factory to demonstrate our production capacity, quality controls, and supply chain transparency.
Detailed technical answers addressing standard dimensions, load capacity, finishes, and corrosion resistance.
While the terms are often used interchangeably, standard "Acorn Nuts" usually feature a lower profile, rounded dome. "Crown Cap Nuts" (often reference standard DIN 1587) typically have a taller, distinct crown shape that offers extra clearance for longer protruding threads, making them ideal for structural assemblies with variable bolt lengths.
Welded caps are made by spot-welding a thin sheet metal dome onto a standard hex nut. Under high vibrations, these welds can fail, causing the cap to separate. Sinsun's one-piece cold-formed cap nuts are forged from a single metal blank, ensuring a continuous grain structure, higher fatigue limits, and zero risk of dome detachment.
We provide zinc plating, yellow zinc coating, hot-dip galvanizing, nickel plating, and chrome coatings. For marine or harsh outdoor environments, we offer A2 (SUS304) and A4 (SUS316) stainless steel cap nuts that resist oxidation and chemical exposure.
Our internal quality control team monitors manufacturing to guarantee ±0.02mm dimensional accuracy. We use Go/No-Go thread gauges to verify that every batch meets the required 6H/6g thread standards, ensuring smooth installation and reliable clamp force.
For standard sizes, we keep ready stock in our 12,000 sqm warehouse, allowing for low MOQs. For custom sizes, materials, or special coatings, the MOQ typically ranges from 50,000 to 100,000 pieces depending on the design specs.
Explore Sinsun Hardware's broader range of screws, bolts, and tools developed for industrial applications.
Get in touch with Sinsun Hardware's engineering team for custom drawings, pricing, and sample delivery.
