What Are the Installation Requirements for Embedded Countersunk Bolts?

The pre-embedded socket is a key component connecting GRC components to the main structure, and its installation quality directly affects curtain wall safety. Based on 28 years of installation experience, Qinglong Group holds that the installation of pre-embedded sockets must meet three core requirements: precise positioning, reliable anchoring, and anti-corrosion durability. Connection safety is ensured through standardized operations and strict inspection.

Precise positioning is the foundation of installation. Socket position deviation should be controlled within ±3mm, with verticality deviation ≤1°. Qinglong Group applies 3D laser scanning technology for precise positioning on formwork, and after drilling uses a feeler gauge to check the hole diameter (1-2mm larger than the bolt diameter). In the Shenzhen Pingshan High-tech Zone Comprehensive Service Center project, positioning molds were fabricated so that the installation error of all 2000 sockets was kept within ±2mm. Socket embedding depth is determined by pull-out force, generally not less than 60mm, while the exposed length allows an adjustment margin (typically 20-30mm).

Reliable anchoring ensures connection strength. The pull-out resistance of sockets must reach 1.5 times the design value or more (usually not less than 10kN). Qinglong Group uses chemical anchor bolts at critical locations, with anchoring adhesive fullness reaching over 95%. Torque control is key: M12 socket torque is controlled at 40-50N·m, installed with a torque wrench, with deviation not exceeding ±5%. Pull-out tests are carried out within 24 hours after installation, with a sampling ratio of no less than 3% and a required pass rate of 100%.

Anti-corrosion durability guarantees long-term safety. 316 stainless steel sockets are used in coastal or high-humidity environments, and 304 stainless steel in normal environments. Qinglong Group coats socket surfaces with epoxy zinc-rich paint (dry film thickness ≥80μm) and seals them by grouting after installation. The anti-corrosion coating is inspected regularly, and any rust found is treated promptly. Through strict installation control, pre-embedded sockets can meet a 50-year service life requirement.