On Feb 17, 5:33*pm, Stoatgobbler
wrote:
Hi there,

Does anyone know if there is a reason why I cannot mount toroidal
transformers one on top of another (stacking them) with a single metal
mounting bolt going through both? I can't see anything on the web which
suggests I don't do this.

Stoat

The strongest magnetic field is produced in a rod shape through the
center of the toroid, when stacking them make sure to orient them both
with the same side facing up, or to put it another way, opposite sides
facing each other if non-horizontally mounted. If they are ran near
capacity, they will stay cooler if you do not block one of the larger
sides with another (heat-producing) transformer.