When sourcing container hooks, the most critical factor is the Working Load Limit (WLL), which must align with your specific lifting requirements (typically ranging from 12.5 to 70 tons per set). You must ensure the hooks are manufactured from Grade 80 (G80) or Grade 100 alloy steel, which provides the necessary strength-to-weight ratio and durability. Additionally, verify the surface treatment, such as powder coating or galvanization, to prevent corrosion in maritime or outdoor environments. For specialized applications, check if the hooks are designed for left, right, or straight lifting to ensure proper engagement with the container corner castings.