Best Cavity Wall Screw Fixings Suppliers & Factory

Cavity wall fixings are engineered specifically to span an air gap or thermal insulation layer while simultaneously bridging two dissimilar structural mediums (e.g., an exterior brick facade/cladding and an inner concrete, aerated block, or light-steel framing substrate). Unlike standard expansion bolts, which rely solely on solid mechanical friction along a single solid plane, cavity fixings must withstand substantial bending moment forces (cantilever shear stress) caused by the cavity gap. Furthermore, they feature dual thread pitches or specialized expansion sleeves to maintain retention without crushing delicate hollow core materials.

Galvanic corrosion occurs when two dissimilar metals with different electrode potentials (such as aluminum alloy 6005-T5/T6 and carbon/stainless steel) are placed in direct electrical contact in the presence of an electrolyte (moisture, rainwater, or salt mist). To prevent electrolytic degradation, engineers must specify high-grade EPDM vulcanized isolating washers, polyamide sleeves, or organic barrier sealants. When mechanical requirements dictate metal-to-metal contact, austenitic AISI 316 (A4) stainless fasteners or zinc-nickel electroplated hardware are strongly specified to minimize potential difference.

For hollow brick or perforated clay blocks, anchors require a minimum embedment depth that bridges across at least two outer web cavities—typically between 50mm and 70mm, frequently combined with mesh sleeves when chemical injection anchors are deployed. In aerated concrete (AAC), specialized spiral or helical fixings typically require an embedment of 60mm to 90mm to achieve requisite pull-out capacities (2.5kN to 5.0kN). Concrete and dense masonry backings generally operate on standard embedment calculations of 4.5 to 8 times the nominal anchor diameter.

Yes. Handan Youlong operates in-house high-speed multi-station cold heading machinery, progressive stamping presses, and CNC thread rolling lines. We manufacture custom lengths, non-standard thread pitches, specialized washer head profiles, and customized drive interfaces (TORX, tamper-proof, hex washer). Customers can provide 2D/3D CAD models or physical samples, and our engineering team will deliver feasibility validation, tooling creation, and PPAP level documentation within specified timelines.

Every shipment from our factory is accompanied by a certified EN 10204 3.1 Inspection Certificate documenting the chemical heat analysis of raw materials and mechanical testing results (tensile breaking load, proof stress, hardness, and coating thickness). Additionally, we provide salt spray test records (ASTM B117 / ISO 9227) and dimensional measurement logs from automated optical sorting machinery. Third-party inspections via SGS, BV, or TÜV are routinely accommodated upon request.