Shackle er ómissandi rigging aukabúnaður í lyftingu byggingarstarfsemi. Hægt er að nota fjötra til að tengja lyftiskífur og fastar stroffur. Það er létt og sveigjanlegt tengitæki sem er mikið notað.Fjötramá skipta í boga fjötra og U-laga fjötra í samræmi við útlitseinkenni þeirra. Í samræmi við tilganginn eru: keðjubönd, akkerisfestingar og fljótandi fjötra.
(1) Keðjanfjötra is a fjötra used to connect the anchor chain. When in use, the horizontal bolt should be upward, and the horizontal bolt should be round to prevent it from rotating in the bolt hole and increase its strength. When using, first take out the horizontal bolt of the fjötra, put the U-shaped buckle into the anchor chain ring to be connected, and then connect the horizontal bolt in series to an anchor chain ring above. In order to prevent the horizontal bolt from coming out, there is an oblique hole at each of the two ends of the horizontal bolt and the U-shaped buckle for driving the brake oblique pin. In order to prevent the oblique pin from coming out, a green lead seal should be inserted into the cavity left at the pin hole. Before the oblique pin is inserted into the pin hole, calcium-based grease should be applied to prevent rust.
(2) Akkeri fjötra is the fjötra used to connect the anchor chain and the sinker, and the method of use is the same as the chain fjötra.
(3) The floating fjötra is the fjötra used to connect the floating body and the anchor chain, and the method of use is the same as the chain fjötra.
