Views: 0 Author: Site Editor Publish Time: 2026-10-21 Origin: Site
Securing structural brackets, baseplates, cable trays, and machinery to concrete traditionally relied on sleeve expansion anchors or chemical adhesive studs. However, modern commercial and industrial projects present constraints:
Close Edge Distances & Spacing: Expanding metal sleeves exert outward radial pressure that can crack concrete near slab edges or narrow support columns.
Temporary Fixture Removal: Expansion anchors cannot be removed cleanly without torch-cutting protruding studs or damaging the floor slab.
Installation Speed & Labor Cost: Standard expansion anchors require hammering, washer placement, and manual torque wrench calibration. Concrete screws drive directly into drilled holes in a single step using standard impact wrenches.
┌────────────────────────────────────────────────────────────────────────┐ │ MASONRY ANCHORING MECHANISMS │ ├──────────────────────────────────┬─────────────────────────────────────┤ │ 1. Direct Concrete Screw │ 2. Traditional Wedge Anchor │ │ [Induction-Hardened Thread] │ [Tapered Wedge Cone] │ │ ▼ │ ▼ │ │ Cuts mating female threads │ Forces metal sleeve outward │ │ into concrete hole wall │ Generates intense radial stress │ │ (Zero expansion bursting) │ (Requires wide edge clearances) │ └──────────────────────────────────┴─────────────────────────────────────┘
Self-Tapping Thread-Cutting Profile: The lead threads of the concrete screw are induction-hardened and engineered with sharp relief flutes that pulverize concrete aggregate and cut continuous female threads into the masonry hole wall.
Interlocking Mechanical Grip: Clamping force is distributed along the full embedment depth of the screw, rather than concentrated at a single localized expansion point.
Complete Removability: The screw can be backed out cleanly with a reverse driver, leaving an empty threaded hole that can be patched flush with grout.
| Evaluation Metric | Direct Concrete Screws (Screw Anchors) | Mechanical Wedge Expansion Anchors |
|---|---|---|
| Expansion Stress on Substrate | Zero Expansion Stress (Suitable for close edges) | High Radial Bursting Stress |
| Minimum Edge Distance Required | Approx. 3× to 5× Bolt Diameter | Approx. 8× to 10× Bolt Diameter |
| Removability | 100% Fully Removable & Reusable | Permanent (Requires grinding off exposed studs) |
| Installation Process | Drill hole → Clean dust → Direct drive with impact tool | Drill hole → Clean → Hammer in → Manual torquing |
| Typical Applications | Racking baseplates, MEP pipe brackets, formwork | Primary structural columns, heavy elevator guide rails |
Answer: Drilled hole depth and dust evacuation. The drilled hole must be at least 10–15mm deeper than the screw embedment depth to accommodate residual concrete dust displaced during the thread-cutting process. Failing to clean the hole or provide extra depth can cause the screw to bottom out and seize prematurely.
Answer: Yes, concrete screws can be reused in temporary installations (such as formwork bracing), provided the cutting threads are inspected and show no severe abrasive wear. However, for permanent structural installations, installing fresh screws into newly drilled holes is recommended.
Ningbo Donghuang Hardware provides industrial concrete screws in hexagonal washer head and countersunk profiles with protective zinc plating and ruspert anti-corrosion coatings.
Product Catalog: View concrete screws and fasteners at dh-hardware.com/Screw-pl49811397.html.
Direct RFQ: Email specifications to tony@wf-fastener.com or call +86-13355841616.
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