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 (with over 18,000+ pallet capacity), and multi-language customer support centers.
Our yearly supply of over 8,500 containers consistently services key global markets such as the Middle East, Southeast Asia, South America, and Russia. Through structural integration and technological innovation, we deliver unparalleled value to our international partners.
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 metric flange nuts, each undergoing 12+ stringent quality checks to assure outstanding polish (Ra ≤ 0.4μm), corrosion resistance (1,000+ hours salt spray test), dimensional accuracy (±0.02mm), high strength (1,000+ MPa), and consistent hardness (HRC 28-32).
We specialize 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 project specifications.
Get a Quick QuoteOur metric flange nuts are manufactured in strict compliance with DIN 6923, ISO 4161, and EN 1661. This ensures universal interchangeability in mechanical assemblies and structured designs across high-stress sectors.
Available in Carbon Steel (Class 8, 10, 12) and Stainless Steel (A2-70, A4-80). These grades are selected to optimize tensile strength, yield limits, and fatigue performance under continuous loads.
Offering both non-serrated configurations for even stress distribution and locking serrated faces that grip the mating surface to prevent loosening caused by structural vibration.
Metric flange nuts combine a standard hexagonal hex nut and an integrated washer-like flange base. In industrial engineering, this configuration provides a major mechanical advantage. The integrated flange distributes the clamping load over a significantly larger surface area than a standard nut. This decreases the surface pressure on the fastened component, minimizing the risk of deformation, crushing, or indentation of softer alloys, plastics, or composite panels.
Additionally, our design eliminates the need for separate washers, streamlining assembly lines and reducing procurement lists. In vibratory environments, the serrated variant acts as an integrated locking mechanism. The angled serrations are engineered to resist counter-clockwise rotation, maintaining consistent torque retention even under cyclic temperature variations and structural vibrations.
Explore our journey of strategic manufacturing upgrades, product expansions, and capacity increases since our founding in 2006.
Sinsun began with a singular focus: to build a factory dedicated to self-tapping screws. This specialization established our core expertise from the ground up.
Establishment of our Export Department. Specialized self-tapping screws and metric industrial nuts began reaching global customers.
Added four spheroidizing furnaces for raw material processing and wire drawing capabilities. Quality control shifted to the raw materials stage.
Enhanced our machinery with German multi-station cold heading systems. Expanded production to drill tail screws and metric flange nut lines.
Reached 36,000 tons in annual production capacity, fulfilling international orders across more than 1,100 export containers.
Inaugurated our 12,000 sqm warehouse, holding extensive ready stock to support daily distribution requirements with short lead times.
Added 4 new continuous atmospheric control heat treatment lines, guaranteeing delivery schedules and consistent metallurgic hardness.
Integrating real-time MES systems and automated vision inspection for zero-defect fastener shipments.
Quality control begins at the source. We start with premium raw materials from XING TAI Steel, then perform in-house spheroidizing annealing and precision wire drawing in our own plant. This guarantees superior microstructure, consistency, and performance in every metric fastener we produce.
Procuring high-grade alloy carbon steel and austenitic stainless steel directly from Xingtai Iron & Steel.
Relieving internal stresses in gas-fired computer-controlled furnaces to improve cold heading properties.
Multi-station cold heading machinery imported from Germany shapes the nut blank and flange with high dimensional accuracy.
Executing carburizing, hardening, and tempering across 4 continuous lines to lock in tensile properties.
Metric flange nuts play a vital role in heavy industrial engineering. Standard hex nuts can fail under high vibrational stresses, leading to clamp force loss. Sinsun's metric flange nuts act as dedicated structural components that stabilize heavy assemblies.
Dynamic load distribution with Class 10/12 flanged lock nuts, resisting thread stripping under thermal cycles.
Stainless Steel A4-80 metric flange nuts provide long-term resistance to acid rain, coastal humidity, and wind loads.
Serrated designs lock securely against structural framework, reducing maintenance demands.
Specialized thread pitches prevent loosening from the high-frequency vibration of passing trains.
With an 18,000+ pallet capacity, our logistics facility tracks stock levels in real time to ensure prompt delivery of standard orders.
Handling every stage of production under one roof, from raw wire drawing and cold forming to heat treatment and final coating.
Our Quality Assurance department tests dimensions, surface roughness, thread alignment, and tensile strength at multiple production stages.
As fastener design advances, modern industrial applications demand thinner coatings with higher corrosion resistance, lighter weights, and smart installation feedback. Sinsun's R&D department continues to develop new surface treatments and alloys to meet these needs.
We are working to integrate zinc-flake and eco-friendly electroplating coatings that offer over 1,500 hours of salt spray resistance without causing hydrogen embrittlement in Class 10.9 or 12.9 high-tensile fasteners. Our team is also developing lightweight aluminum and titanium alloy metric flange nuts to help reduce weight in electric vehicle chassis and aerospace assemblies.
We are researching smart washers and flange nuts with integrated piezoelectric thin-film sensors. These fasteners will be able to measure clamping force and report real-time structural tension data back to centralized control systems.
This technology will allow infrastructure projects, industrial turbines, and deep-sea drilling platforms to identify loosened fasteners before structural failure occurs, reducing inspection downtime.
Our manufacturing facility operates under ISO 9001:2015 and CE certification standards. We supply full inspection documents, material test reports (MTR), and REACH/RoHS compliance declarations with every shipment.
We offer flexible OEM and ODM packaging options, including small custom-labeled boxes, heavy-duty polypropylene bags, and ocean-ready wooden crates. We can also provide 3D packaging mockups before final production.
Shipping over 8,500 containers annually gives Sinsun strong relationships with major ocean freight carriers. We manage complex customs requirements to deliver your fasteners on time under FOB, CIF, or DDP terms.
Every month, we welcome international buyers for on-site factory audits. Sinsun exhibits at major global industrial trade shows to connect with distributors and show our latest product lines.
DIN 6923 is the historical standard for hex flange nuts, while EN 1661 is the newer European standard. They have similar thread pitches and nominal sizes, but they differ slightly in overall height, flange diameter tolerances, and width across flats for some larger thread sizes. Our engineers review your technical drawings to ensure we deliver nuts that meet your application's exact clearance requirements.
Serrated flange nuts have angled teeth on the bearing surface. During installation, these teeth lock into the surface of the joint. When vibrations try to turn the nut counter-clockwise, the teeth bite into the material and resist backing off. Note that because they bite into the material, serrated flange nuts can scratch painted or coated surfaces. Smooth flange nuts are better for applications where preserving surface coatings is a priority.
We offer various coatings depending on your environmental requirements, including zinc plating (clear, yellow, or black), hot-dip galvanizing for construction, and advanced organic zinc flake coatings. Zinc flake coatings provide excellent corrosion protection for marine or solar energy applications without causing hydrogen embrittlement in Class 10 or 12 high-tensile steel.
Yes. Sinsun's technical department can customize standard flange designs to meet your requirements. We can manufacture custom thread pitches (fine/extra-fine) and oversize or undersize flange diameters. Our production team uses custom cold heading dies and high-precision tooling to maintain tolerances of ±0.02mm.
Need Class 8, 10, or 12 metric flange nuts in bulk? Our engineering team is ready to assist with sizing, drawing reviews, and custom packaging designs. Contact us today to receive a detailed quote within 24 hours.
