Browning is used as corrosion protection of steel parts, but also as decorative coating of e.g. rifle barrel and knife blades. But also many tool parts are browned as browning gives good corrosion protection and less coefficient of friction.
Browning is in short terms a chemical process actually rusting the work piece surface during controlled conditions.
As the work piece is put in a liquid tub it is browned no matter its geometry.
Unit size: 1100 x 600 x 400