Rigging common sense: why can't the shackle be replaced by an S hook
In some construction sites, in order to save trouble, S-shaped hooks are often used instead of shackles for hoisting. So is this approach advisable? The answer is no, why can't the shackle be replaced by an S hook?
First of all, a comparative analysis is made on the material. The rebars used in the construction site are often HRB335 or HRB400 hot-rolled ribbed steel bars. These two kinds of steel bars have something in common.
The elongation of these two steel bars is not less than 25% of the first-grade steel HPB230 or the current HPB300 steel bar, and the elongation of 16% of HRB335 and 14% of HBR400 is much "shabby". Because the larger elongation rate can ensure that if there is any variation during the hoisting process, the construction personnel can find it immediately and will not cause a safety accident.
Shackles made by professional manufacturers are guaranteed in terms of material and safety factor. Therefore, it can be used with confidence on the construction site. Compared with the S-shaped hook processed from rebar, the safety cannot be guaranteed first in terms of material, let alone the insurance factor. Therefore, once the construction team processes the rebar into S-shaped hooks without permission at the construction site, they should be severely punished.