The chain diameter and lifting length of the chain block are different, which determine the different lifting tonnage and the number of lifting chains used. For the number of chain lines, the 1t and 2T chain block is a single chain (1), the 3T and 5T chain block is a double chain (2), the 10t chain is 4, and the 20t chain is 8. This chain refers to the lifting chain.

For chain diameter, there is only one chain with a diameter of 6mm at the hook link of 1t chain block, 8mm for 2T and 3T chain blocks, and 10mm for 5T, 10t and 20t chain blocks.

When using single chain manual hoist to lift goods, it is more labor-saving than double chain chain. However, its lifting capacity is reduced by half. The double chain is not only more powerful than the single chain, but also easier to pull than the single chain. However, the lifting speed is half that of the single chain. Generally speaking, two tons and more use double chain to work.