What is a bridge horseshoe magnet?

A bridge horseshoe magnet is used to hold ferromagnetic materials in a certain position for welding, for example holding two pieces of steel together to create a sign.

It is a type of horseshoe magnet that has a very small air gap in between the two magnetic poles. This is because the small air gap creates a shorter circuit for the magnetic field lines to travel, making the magnet stronger, which gives the magnet increased grip on pieces of steel for welding. 

It is also thicker than any other variety of horseshoe magnet due to the nature of its uses. The pieces of steel need to be held firmly in place, this is achieved by the depth of the bridge horseshoe magnet.