Use these hoist rings to attach directly to your Grade 80 lifting chain--the pocket on these hoist rings accommodates a specific size of chain, from 1/4" - 5/8" depending on the model. You may use Grade 100 chain, but be advised the rating of the hoist ring is still only at the Grade 80 level. Available in capacities from 4,500 - 18,100 lbs and thread diameters from 5/8" - 1-1/4". Each hoist ring is proof-tested to 2-1/2 times the Working Load limit with certification. They are fatigue rated to 20,000 cycles at 1-1/2 times the Working Load Limit. Each hoist ring also has a Product Identification Code (PIC) for complete material traceability. Design factor of 4:1.