Qingdao Haosail Machinery Co., Ltd.

US Type Clevis Slip Hook with Latch 331C, 331A Features:

• Clevis Base Design for Rigid, Tool-Free Installation. At the shank end, the 331C/331A features a U-shaped clevis structure (a defining trait of US-type rigging hardware) with a precision-drilled hole. This design enables fast, secure attachment to fixed anchor points (e.g., trailer D-rings, truck bed tie-downs, or shackles) using standard cotter pins, hairpin clips, or bolts—no specialized tools required. The clevis ensures a non-rotating, stable connection, preventing the hook from shifting during load tensioning or highway transit, which is critical for maintaining alignment with US DOT load-securing requirements.

• Slip-Style Throat for Flexible Chain Positioning. The hook’s wide, smooth throat is engineered for "slip" functionality, allowing it to glide freely along the length of compatible G70/G80 chains (the US industry standard for heavy-duty transport). Unlike grab hooks (which lock onto specific links), this design lets operators adjust the hook’s position on the chain quickly—even under moderate tension—without disassembling the rigging. This flexibility is ideal for securing variable-sized cargo (e.g., pallets, machinery, or bulk goods), streamlining workflows in busy US freight yards or construction sites.

• Spring-Loaded Safety Latch for Anti-Disengagement Protection. A critical upgrade over standard slip hooks: the 331C/331A includes a heavy-duty, spring-loaded safety latch (also called a "keeper") that covers the throat opening. The latch automatically closes and locks into place once the hook is attached to a chain link or anchor, creating a fully enclosed connection. This prevents accidental load detachment caused by vibration (e.g., during highway braking), sudden cargo shifts, or operator error—directly aligning with OSHA’s rigging safety guidelines (29 CFR 1910.184) to reduce accident risks. The latch is also easy to manually open (via a small, ergonomic tab) for quick hook placement/removal.

• G70-Grade Alloy Steel Construction for US-Style Durability. Manufactured from heat-treated G70 alloy steel—the benchmark for US heavy-duty load-securing components. The steel undergoes quenching and tempering to enhance tensile strength, impact resistance, and wear resistance, enabling the hook to handle working load limits (WLL) ranging from 5,000 to 16,000+ pounds (varies by size). This construction resists deformation, bending, or cracking even under extreme tension (e.g., securing heavy machinery on flatbeds) and meets the rigorous durability demands of US industrial and transportation sectors.

US Type Clevis Slip Hook with Latch 331C, 331A Typical Applications:

• Construction field: On construction sites, it can be used to hoist construction materials such as steel bars and formwork, and cooperate with equipment such as cranes to hoist materials from the stacking place to the designated construction location. It can also be used for the installation and disassembly of construction equipment. For example, during the installation of tower cranes, the lifting chain and tower crane components can be connected by sliding hooks to ensure accurate installation of components. It can also be used for the cleaning and transportation of construction waste. After the waste is bundled, it is connected to the transportation equipment through the sliding hook for lifting.

• Industrial manufacturing and maintenance: The sliding hook is often used in the installation, commissioning and maintenance of equipment in the factory. For example, when relocating large machine tools, the machine tools are connected to the lifting tools through the sliding hook to achieve stable lifting and positioning of the machine tools. In the maintenance of production line equipment, it can be used to lift parts and components to facilitate maintenance personnel to carry out maintenance work. At the same time, when installing industrial pipelines, it can help hoist pipeline components to ensure the accuracy and efficiency of pipeline installation.

• Freight transportation industry: In road transportation, it is often used to fix cargo on vehicles such as trucks and semi-trailers. Combine the sliding hook with the binding belt or chain, bypass the cargo and fix it, which can prevent the cargo from moving due to bumps during transportation. In rail transportation, it can be used for loading and unloading and fixing of railway truck cargo, connecting the fixing device in the truck compartment with the chain on the cargo to ensure the safety of cargo transportation. In air cargo transportation, for the ground transportation of some large aviation parts, the sliding hook can also be used for auxiliary fixing and lifting, which is convenient for the transfer of cargo in the airport.

• Port and ship operations: In port loading and unloading operations, it can be used to lift containers and various types of bulk cargo, and cooperate with port cranes and other equipment to achieve rapid transfer of cargo between ships and docks. On ships, it can be used for lifting and maintenance of ship equipment, such as lifting lifeboats and engine parts on ships. At the same time, when the ship is moored, the mooring chain can be connected to the dock mooring device, and the locking function of the sliding hook can be used to ensure the stability of the ship's mooring and resist external forces such as wind and waves.

• Power and energy industry: In power engineering construction, it can be used to lift power equipment such as poles and transformers, and cooperate with cranes and other tools to lift the equipment to the designated location for installation. In wind farms, it can be used for the hoisting and maintenance of wind turbine blades, towers and other components. The lifting rigging is connected by sliding hooks to ensure the safe installation and maintenance of wind power equipment. In the petrochemical industry, it can be used to hoist large reactors, oil storage tanks and other equipment, as well as to hoist pipeline components during pipeline laying, meeting the high-demand hoisting operation needs in the industry.

• Agriculture and gardening operations: In agricultural production, it can be installed on agricultural machinery such as tractors to tow agricultural machinery such as planters and harvesters, adapt to complex road conditions in the field, and ensure reliable connection during traction. In garden construction, it can be used to hoist large trees to facilitate the transplanting and planting of trees. It can also be used for the hoisting and transportation of garden machinery and equipment. For example, when transporting garden pruning vehicles and other equipment from one place to another, the sliding hook can be used for fixing and hoisting.