While there are several types of belt buckles --- such as plastic snap buckles used for woven belts or decorated clip belts featured in Western-style belts --- tang belt buckles are arguably the most common type of belt buckle. Such buckles are made up of a metal ring with a hinged flap (the tang or pin), which is pushed through a hole in the belt to secure it. Tang belt buckles are often used in leather belts, and while the tang can loosen, wear down or snap off, they are fairly easy to repair using a wire hanger.
Unscrew the buckle from the belt. Most belt buckles are screwed into the belt via two small screws. Use a flathead screwdriver to gently remove these screws from the belt.
Cut or snap off the damaged belt buckle pin. Cut off the loop portion of the wire hanger with wire cutters. Position the hanger on the belt where the pin was previously looped. Use wire cutters or your scissors to bend and shape the hanger around the buckle. Wrap the hanger around the buckle tightly to secure it.
Trim the remaining end of the hanger with the wire cutters, if necessary. If the wire has sharp edges, use a metal file to smooth the sharp parts. Screw the buckle back into the belt and try it on to ensure the buckle works properly.
If your belt buckle pin broke off and part of it remains wrapped around the buckle use wire cutters or pliers to remove the excess wire. Replace a belt by unscrewing the belt buckle and attaching it to another belt.