Pressed Steel Grille
Originally intended for use in the warm air heating systems of the 1970's and 80's, pressed steel grilles are now little more than of use as replacement parts in some aspects.
They do continue to have uses outside of replacement parts though. Pressed steel grilles can be combined with S300 in-door fire dampers in fire doors. Registers combine a grille with a damper to produce an extremely easy tooperate unit, with volume control integrated.
Pressed steel grilles are exactly that; pressed directly from sheet steel.