1.What lifting equipment is mainly used for hoisting horizontally laid cold-rolled coils?
The most commonly used lifting tool for horizontally laid (laying) steel coils is the C-type spreader, also known as a C-type coil hook.
The C-type spreader is named for its resemblance to the letter "C" and is specifically designed for the horizontal lifting of steel coils. Its main body is made of box-shaped steel plates and equipped with counterweights to adjust balance, ensuring that the center of gravity of the spreader and the load are aligned, thus guaranteeing stable lifting. This type of spreader is widely used in steel mills, warehouses, docks, and other locations, with a load range typically from 3.2 tons to 32 tons. Its advantages include relatively low cost and easy maintenance, but its disadvantages include specific requirements for the stacking spacing of steel coils during lifting and relatively lower operational efficiency.
2.Besides C-type spreaders, what other common lifting methods are there?
For scenarios requiring higher precision or protection of the steel coil's surface quality, a "dedicated lifting sling + balanced lifting beam" approach is more commonly used.
This method utilizes high-strength synthetic fiber lifting slings (or hoisting slings) in conjunction with an inverted "T"-shaped or I-shaped balanced lifting beam. Two adjustable inner lifting rings are located on the underside of the lifting beam; the slings pass through these rings and support the bottom of the steel coil. The advantages of this structure are:
Surface Protection: The slings maintain a soft contact with the steel coil, effectively preventing scratches.
Optimal Stress Distribution: The spacing between the two lifting rings can be adjusted according to the coil's width, creating a larger angle between the slings and the coil's edge, reducing pressure and damage from the coil's edge.
Wide Applicability: Particularly suitable for lifting pre-packaged cold-rolled finished coils with extremely high surface quality requirements.
3.Why is it emphasized that "special slings" should be used at the dock or in some on-site reports?
This is mainly due to the delicate nature of cold-rolled coils-they have high surface precision and smoothness, and are beautifully packaged, making them highly susceptible to damage from bumps and scratches during lifting.
Using ordinary steel wire ropes for direct lifting can easily damage the edges of the coil and even the inner coil itself. Therefore, professional operations employ strict protective measures:
Using specialized lifting slings: High-strength synthetic fiber slings are used instead of steel wire ropes to avoid hard contact from the outset.
Installing protective sleeves: Before lifting, protective sleeves are installed at easily worn areas such as the right angle between the slings and the inner coil of the coil to prevent the sharp edges of the coil from cutting the slings and to further protect the coil.
Smooth operation: Lifting and lowering the coil are done smoothly to avoid damaging the slings and the coil due to acceleration or impact.
4.What are the essential safety guidelines that must be followed when using and maintaining lifting equipment?
Overloading is strictly prohibited: Each type of lifting equipment has a clearly defined rated lifting capacity; overloading is strictly prohibited during use.
Regular inspection: For major load-bearing components (such as lifting rings, lugs, and twist locks), a comprehensive inspection should be conducted at least every 3 months under normal use to check for cracks, severe deformation, or wear.
Daily maintenance:
Regularly lubricate rotating parts to prevent dry friction or jamming.
After use, store on a dedicated rack in a well-ventilated, dry, and clean workshop, and take precautions against rust.
Smooth lifting: During lifting, lift smoothly to avoid collisions between the lifting equipment and steel coils or other equipment that could cause deformation.
5.If you need to lift a vertically placed cold-rolled coil (vertical), what kind of lifting equipment should you use?
When hoisting coils vertically (in a vertical position), specialized vertical coil lifting equipment is required.
When cold-rolled coils need to be uncoiled on the production line or stacked vertically in a warehouse, the lifting equipment also needs to be changed accordingly. The design of vertical lifting equipment is completely different from that of horizontal equipment. It typically uses a three- or four-legged chain sling with specially designed hooks or clamps at the ends. These hooks precisely engage the inner or outer edge of the steel coil, and through the lifting of the crane, utilize leverage or its own weight to clamp and achieve stable vertical lifting. This type of lifting equipment is more specialized and is usually customized according to the specific dimensions and weight of the steel coil.