It is a 2" Male Hinge

or end post to hide any sharp post edges and protect from water damage

These inserts are designed to help support the weight of your gate and give the screws for hinges something stronger to grip into

Fences topped by barbed wire remains a common installation at power plants

6-5/8” post

5" Black Barrel Hinge Pair AFC-018 It is a 2" MaleWith a 600 pound holding capacity and only 5 inches in length, this 5 Black Barrel Hinge is the strong, sturdy hinge you need for your door or gate. This hinge has a 5 8 diameter pin with a ball bearing and grease fitting for lubrication. Galvanized steel Black coating 5 8 diameter pin