When using a flat sling with soft lifting eyes, the minimum length of the lifting eye used should not be less than 3.5 times the maximum thickness of the hook in contact with the lifting eye, and the angle of movement of the lifting eye should not exceed 20 °.
When connecting slings and lifting appliances with soft lifting eyes, the contact part between the slings and lifting appliances must be continuous, unless the axial width of the slings does not exceed 75mm, and the bending radius of the lifting accessories must be at least 0.75 times the axial width of the slings.
The evaluation of the ultimate working force of multiple composite slings depends on the symmetry of the load borne by the composite slings, that is, when lifting, the branches of the slings are symmetrically and evenly distributed according to the design, with the same vertical angle. If the branch cannot be uniformly stressed as designed, and the maximum force is on a branch, it will be the sum of the maximum forces borne by the adjacent branches at the design angle. Additionally, if it is not a rigid load, it will also be counted.