Flower Expansion Anchor (Heavy-Duty Multi-Wedge Anchor) | Premium Mechanical Lock for Critical Structural Connections
Product Overview
The Flower Expansion Anchor, also known as a Heavy-Duty Multi-Wedge or Undercut Anchor, is a high-performance mechanical anchor engineered for the most demanding structural fastening applications in concrete. Its namesake “flower” or multi-wedge design features several independent, hardened steel expansion segments that deploy uniformly against the concrete upon tightening, creating an exceptionally large and secure bearing surface. This mechanism offers unparalleled pull-out strength, shear capacity, and vibration resistance, making it the preferred choice for safety-critical connections, seismic applications, and scenarios with high dynamic loads or minimal edge distances.
Key Advantages
Exceptional Load Capacity: The multi-wedge design distributes clamping force over a larger area of the concrete, resulting in significantly higher tensile and shear values compared to standard sleeve or wedge anchors of the same diameter.
Superior Performance in Cracked Concrete: Specifically designed and tested to maintain holding power in cracked concrete conditions, often complying with the highest categories of international approval guidelines (e.g., ETAG 001 C1).
Excellent Vibration & Shock Resistance: The uniform mechanical lock provides outstanding resistance to dynamic loosening forces, ideal for machinery bases, railings, and structures in high-traffic or seismic zones.
Reduced Concrete Stress: Provides high load capacity with relatively low expansion pressure, minimizing the risk of concrete spalling, especially near edges or in brittle materials.
Verifiable Installation: Correct installation is visually and mechanically verifiable, ensuring reliability.
Material Specifications & Construction
Stud/Bolt: Manufactured from quenched and tempered alloy steel to Grade 10.9 or 12.9 (ISO 898-1), providing ultra-high tensile strength.
Expansion “Flower” Segments: Precision-formed from case-hardened steel for maximum durability and consistent expansion behavior.
Nut & Washer: Matched high-strength nut and large, hardened washer to distribute load and complete the assembly.
Available Finishes: Offered in various high-corrosion-resistant finishes to suit the environment:
Hot-Dip Galvanized (HDG): Per ISO 1461 for severe outdoor exposure.
Zinc-Nickel Alloy Plating: For automotive-grade corrosion resistance.
Stainless Steel A4 (316): For highly corrosive (marine, chemical) environments.
How It Works: The Multi-Wedge Mechanism
Drilling: A standard diameter hole is drilled to the specified depth.
Insertion: The anchor is inserted through the fixture into the hole.
Tightening: As the nut is tightened, a conical plug is drawn upward, forcing the multiple independent steel segments (“petals”) to expand outward radially and uniformly.
Locking: The segments create a powerful, mechanical interlock with the concrete over a broad surface area, achieving its high load rating.
Performance Data & International Approvals
Certifications: Engineered to meet or exceed the requirements for European Technical Assessment (ETA) and ICC-ES Evaluation Reports, allowing for use in calculated structural applications per ETAG 001 and ACI 318.
Fire Resistance: Often available with fire-rated performance data, tested according to relevant standards for maintaining load during fire exposure.
Seismic Performance: Suitable for use in seismic design categories due to its robust and ductile failure mode.
Typical Applications
Structural Steel & Facades: Securing steel columns, beams, and curtain wall brackets to concrete foundations and slabs.
Heavy Machinery & Industrial: Anchoring presses, generators, conveyor systems, and crane rails subject to intense vibration.
Infrastructure & Safety: Bridge expansion joints, highway barrier systems, fall protection lifeline anchors, and stadium seating.
Energy & Power: Securing equipment in wind turbine bases, power plants, and substations.
Quality Assurance
Each anchor is produced under a certified ISO 9001:2015 and often IATF 16949 quality management system. Production includes stringent material certification, dimensional verification, and batch testing of mechanical properties. Full traceability and compliance documentation are provided.
Manufacturing Expertise
The Flower Expansion Anchor series is supplied by Hebei Wohe Fastener Manufacturing Co. Ltd., a manufacturer with deep expertise in high-strength, mission-critical fastening solutions. Our technical partnership with specialized forging and heat-treatment facilities enables us to produce the complex, high-integrity components required for this premium anchor type. We support global engineering and construction firms by providing not only certified products but also technical data for calculation software and guidance for specification in demanding projects.
Ordering & Specification:
Specify: Thread Diameter (e.g., M12, M20), Minimum Embedment Depth, Concrete Strength Class, and Required Finish.
MOQ: Project-based pricing and quantities. Prototype samples available for testing.
Lead Time: Typically 30-40 working days for standard certified configurations.
Disclaimer: This anchor is a structural component. Its selection, design, and installation MUST be performed by a qualified structural engineer in accordance with local building codes and the product’s current, valid approval report (ETA or ICC-ES). Incorrect installation (e.g., insufficient hole depth, incorrect torque) will void performance ratings.
