Premium M6-M20 Undercut Anchors: The Gold Standard for Modern Facades
Our M6-M20 Undercut Anchors, also known as Stone Cladding Back Bolts, represent the most advanced technology in mechanical anchoring for curtain wall systems. Unlike traditional expansion anchors that create internal stress in the substrate, these undercut fasteners lock into a precision-drilled tapered hole. This “positive fit” mechanism ensures that the load is distributed over a larger surface area, making them the safest choice for fragile materials like natural granite, marble, and ceramic panels.
As a specialized undercut anchor factory, we utilize high-grade 316 Stainless Steel to ensure 50+ years of service life in harsh outdoor environments and coastal projects.
- Stress-Free Fastening: The mechanical locking principle eliminates expansion pressure, allowing for installation close to the edges of stone panels without the risk of cracking.
- Invisible Fixation: Installed on the reverse side of the cladding, these back bolts provide a clean, fastener-free aesthetic for modern architectural designs.
- Superior Seismic Performance: Tested to withstand high-vibration and earthquake-prone environments, ensuring the safety of high-rise building envelopes.
- High Load Capacity: Ideal for heavy panels and structural concrete where standard drop-in anchors fail to meet safety margins.
| Thread Size | Drill Depth (h1) | Panel Thickness | Material |
|---|---|---|---|
| M6 | 10 – 15 mm | 12 – 20 mm | SS304 / SS316 |
| M8 | 15 – 25 mm | 20 – 30 mm | SS304 / SS316 |
| M10 | 20 – 40 mm | 25 – 40 mm | SS316 |
| M12 | 40+ mm | Concrete Only | SS316 / Carbon Steel |
| M16 / M20 | Custom | Heavy Concrete | Alloy Steel |
- Natural Stone Cladding: Securely mounting Granite, Marble, and Limestone panels for high-end hotel and commercial exteriors.
- Ventilated Facades: Attaching ceramic, porcelain, and fiber cement boards to sub-frame systems.
- Heavy Machinery: Anchoring equipment to concrete floors where dynamic loads and vibrations are constant.
- Nuclear & Tunnel Engineering: Used in safety-critical structural anchoring due to high pull-out resistance.
A: Yes, undercut anchors require a specific undercut drilling tool that creates the flared “taper” at the base of the hole, allowing the anchor to expand and lock.Q: What is the difference between SS304 and SS316 for back bolts?
A: SS304 is suitable for standard inland environments. SS316 is highly recommended for coastal projects or cities with high pollution levels due to its superior molybdenum-based corrosion resistance.
Source M6-M20 Undercut Anchors from a Professional Factory
Seeking bulk stone back bolts with complete ETA certification and factory-direct pricing? We support global wholesale and technical consulting. Contact us today for a free quote and technical samples!
