Zinc Plated Carbon Steel Concrete Screw Anchor Self Tapping Masonry Bolt Class 8.8 10.9

The Zinc Plated Carbon Steel Concrete Screw Anchor (commonly known as a self-tapping concrete bolt, masonry screw anchor, heavy-duty concrete screw, or hex flange masonry anchor) is an advanced, high-performance mechanical fastener engineered to cut its own threads directly into pre-drilled holes in concrete, brick, hollow block, and natural stone. Featuring specialized hardened cutting threads and a hex flange head with locking under-head serrations, this anchor eliminates the need for expansion sleeves, plastic plugs, or chemical resins. Because it creates an expansion-free mechanical interlock, it allows for significantly smaller edge distances and closer anchor spacing without cracking surrounding concrete, adhering fully to global ISO standards.

Technical Specifications of Self Tapping Concrete Screw Anchors

We produce case-hardened carbon steel concrete screw anchors engineered to achieve high shear and tensile pull-out values equivalent to Class 8.8 and Class 10.9 structural bolts. The serrated flange head locks tightly against fixture plates to resist loosening under vibrational loads.

Precision Manufacturing, Cutting Thread Rolling, and Case Hardening

At our specialized manufacturing facility in Handan, China, concrete screw anchors undergo automated multi-station cold forming, precision thread rolling, case-hardening heat treatment, and surface plating:

• Heavy Multi-Station Cold Heading: High-tonnage cold formers press boron steel wire into precise hex washer heads, stamping locking serrations under the flange that prevent backlash.
• Specialized Cutting Thread Rolling: Precision thread rolling machinery rolls sharp hi-low threads equipped with notched cutting flutes near the tip to carve threads into dense concrete.
• Controlled Carburizing & Tempering Furnace: Mesh-belt continuous heat treatment furnaces infuse carbon into the surface layer, establishing high thread-cutting hardness (≥550 HV) while preserving core ductility to prevent shearing.
• Electro-Zinc Plating & De-Embrittlement Baking: Trivalent chromium (Cr3+) electro-zinc plating provides bright corrosion protection, followed by baking to eliminate hydrogen embrittlement risks.

Key Engineering Applications of Self Tapping Concrete Screw Anchors

Concrete screw anchors are essential fast-installation anchors across construction, MEP, and temporary structural framing:

• Structural Steel Brackets & Formwork Mounting: Fastening temporary concrete shuttering formwork, steel column brackets, and scaffolding wall ties.
• MEP Conduit, Cable Tray & HVAC Ducting: Securing electrical conduit clamps, heavy cable management trays, and air duct hangers to ceilings and walls.
• Close-Edge Balustrades & Stadium Seating: Anchoring guardrails, handrail posts, and venue seating where close edge margins prevent expansion anchors.

Quality Control and Export Packaging for Concrete Screw Anchors

Handan YiHao Fastener enforces strict Quality Assurance (QA) standards for all overseas export orders. Testing procedures include 100% concrete driving torque tests (driving into C30/C40 concrete blocks), pull-out tension tests, case depth hardness testing, and salt spray validation.

All export items are bulk packed in heavy-duty 25kg inner cartons or 1000pcs small color boxes, neatly stacked on ISPM 15 compliant fumigated wooden pallets, and wrapped in protective stretch film for safe ocean freight.