What it’s for
On a new door, the hinge is exposed: you can see the pin, screws and sometimes grease. A hinge cap covers them and gives the hinge the same finish as the handle. When renovating, it also conceals marks left by the old hardware.
How to measure
With the door closed, measure the outside diameter of the hinge barrel using callipers or a ruler. Then measure the visible height between the two leaves. These two measurements are enough to choose a cap.
See also
Explore the rest of our door hardware.