Duplex Stainless Steel L-metal Bolt Foundation Anchor M20 with PTFE Coating for Corrosion-Resistant Marine Applications

Duplex Stainless Steel L-metal Bolt Foundation Anchor M20 PTFE Coating for Corrosion-Resistant Marine Applications
 
 
 
1,Description:

Bolts serve as fundamental fastening elements in the construction industry, performing critical functions that ensure structural integrity, safety, and durability across diverse building applications. Their primary role involves connecting structural members such as steel beams, columns, trusses, and concrete elements, effectively transferring loads and forces throughout the building framework. In steel construction, bolts create rigid or semi-rigid joints that resist shear forces, tension loads, and bending moments, enabling the structural system to behave as a unified entity under various loading conditions including gravity, wind, seismic activity, and live loads.

Roofing and facade applications represent another common use case for hook bolts. Workers install these fasteners through roofing sheets or wall panels into underlying purlins or girts, with the hook end engaging the structural member from below or behind. This installation method eliminates the need for access to the back side of the supporting structure, simplifying assembly and reducing labor costs. The hook provides immediate retention during placement, allowing installers to position components before final tightening, which improves productivity and safety when working at height or in confined spaces.

In temporary construction applications, hook bolts enable rapid attachment and removal of formwork, scaffolding, safety netting, and bracing systems. The quick engagement and disengagement capability supports efficient workflow without sacrificing load capacity or safety. Construction crews use hook bolts to suspend conduit, ductwork, and piping from overhead beams, where the hook end wraps around the beam flange while the threaded portion accepts hangers and clamps. This suspension method accommodates thermal expansion, vibration isolation, and future adjustments more readily than welded or rigidly bolted alternatives.

Material handling and industrial equipment frequently incorporate hook bolts for securing guards, covers, and access panels that require periodic removal for maintenance. The hook end maintains alignment and partial support even when the nut is loosened, preventing components from falling or shifting unexpectedly during service operations. This feature enhances worker safety and reduces downtime in manufacturing facilities, power plants, and processing installations.

The performance requirements for hook bolts emphasize bend geometry, material ductility, and coating durability. The hook radius must accommodate the supporting member thickness without creating stress concentrations that could initiate cracking under cyclic loading. Manufacturers typically form hooks from ductile materials capable of undergoing cold bending without embrittlement, ensuring the curved section retains strength and toughness comparable to the straight shank. Corrosion protection becomes particularly critical at the bend region where coating thickness may vary and mechanical damage during installation can expose bare metal.

In summary, hook bolts fulfill essential fastening roles where mechanical engagement, installation accessibility, and resistance to withdrawal forces take priority over simple clamping action. Their distinctive shape solves practical connection challenges across construction, industrial, and infrastructure applications where standard bolt configurations prove insufficient or impractical.

2,Applications:
Grade 8.8 bolts: tensile strength 800 MPa, yield strength 640 MPa. Suitable for non-extreme load environments such as construction machinery and general industrial assembly, offering good value for money and versatility. They are typically manufactured from medium-carbon steel that has undergone quenching and tempering, such as 20MnTiB. Grade 10.9 bolts: Tensile strength 1000 MPa, yield strength 900 MPa. Commonly used in critical structural components such as automotive applications, bridge construction and high-speed rail, meeting the demands of dynamic loads and high fatigue strength. The manufacturing process is more demanding, and they are generally produced from low-alloy steel (such as 35CrMo) following heat treatment. Grade 12.9 bolts: Tensile strength of approximately 1200 MPa, yield strength of 1080 MPa. These are among the highest-performance carbon steel high-strength bolts currently available on the market. They are commonly used in hydraulic equipment, high-pressure valves, heavy machinery and the mould industry, where they must withstand extremely high loads or impact loads. The manufacturing process involves deep quenching and tempering, as well as ultrasonic testing, to ensure a balance between strength and stability.
When designing engineering solutions or carrying out maintenance, it is crucial to select bolts with the appropriate performance grade based on factors such as load, operating environment and budget. For example:
Building Structures: Grade 8.8 bolts are generally used for steel structure connections, offering long-term durability.
Engines and Transmission Systems: Grade 10.9 or 12.9 bolts are recommended to ensure fastening requirements are met during high-speed vehicle operation. Automotive Manufacturing: Industrial Equipment: Grade 12.9 bolts are recommended for heavy-duty hydraulic machinery and pressure vessels to withstand high-impact forces and high-pressure environments. It is important to note that whilst Grade 12.9 offers higher strength, its machining, cost and tempering stability are more complex; in non-essential applications, it may actually be less practical than Grade 8.8. Therefore, a comprehensive assessment is required during the design phase.

Available in small packing, carton packing, or pallet configurations to meet your shipping and storage requirements.

Manufacturer Information

Manufactured by JIA SHAN Hardware Company with strict quality control measures and pre-shipment inspection.