Eye and Eye Turnbuckles Chicago makes their eye & eye turnbuckles a little different than other domestic manufacturers. They feature a round eye (as opposed to a teardrop shape), which can be great when connecting with an item like a shackle. The round pin of the shackle fits nice and evenly inside the turnbuckle eye. These turnbuckles are made in the U.S.A. (like most Chicago products). They are made from forged, heat treated steel with a hot dip galvanized finish. The load rating is based on a straight vertical load, with a safety factor of 5:1.