Parts of a Door Hinge 

Degol Hardware let you know:

Leaf: also known as the wing, it’s the flat part of the hinge that’s screwed into the door and frame

Knuckle: it’s the middle part, usually cylindrical, where the leaves meet. This is the part that allows the door to move

Pin: a long piece that slides into the knuckle which keeps the two leaves together. When the pin is pulled out, you can remove the door slab from the frame

Sleeves: the round pieces that make up the knuckle which hold the pin in place