For semi-submersible drilling platforms, floating production and storage tankers and other offshore development facilities, mooring chain products are required to not only have high strength and toughness, but also have seawater corrosion resistance, fatigue resistance, wear resistance and other properties of the mooring chain steel due to long-term immersion in sea water. Studless mooring chains are often used for permanent mooring. The absence of a rung reduces the weight per unit strength and increases the fatigue life of the chain. The disadvantage is that it is not very convenient to operate when hoisting.