Open die forging Closed die forging Two flat dies. Used for large objects and

smaller quantities. Simple Inexpensive Wide range of sizes Good strength Difficult to hold close

tolerances Machining is necessary Low production rate Poor utilization of material High skill required.

Two dies with impressions of final shape.

Used for smaller components

Good utilization of material Better properties than open

die forging Good dimensional accuracy High production rate Good reproducibility High die cost for small

quantities Machining often necessary.

Flash: Flash regulates the escape of metal and thus thin flash increases

the flow resistance of the system so that the pressure builds up to high values to ensure that metal fills all recesses of die cavity.

It acts as a safety valve for excess metal in the CD cavity.