A padeye is a device often found on boats that a line runs through, or provides an attachment point. It is a kind of fairlead and often is bolted or welded to the deck or hull of a boat.
It is also used in oil and gas projects to assist in the purpose of lifting.
It's made of steel plate with radius at oneside. lifting is done with the help of D-shackle or sling,which fits into the hole of padeye. there may be one or more circular plates(cheek plates) welded around the hole.