Direct Extrusion Presses

Direct extrusion is a common extrusion forming method. After the billet is loaded into the container, the main extrusion system applies pressure to the billet through the stem and dummy block, causing the metal to flow out through the die opening. The metal flow direction is the same as the main press motion.

1. Billet enters the container at the set temperature condition.
2. The main extrusion system pushes the dummy block and billet toward the die.
3. Relative sliding occurs between the billet and the container wall.
4. Metal forms the target cross-section under pressure through the die opening.
5. After extrusion, the butt is removed and the workpiece enters subsequent pulling, cooling, straightening or cutting operations.

• Solid profiles
• Bars
• Selected tubes produced with appropriate die systems
• Hollow profiles produced with porthole, bridge or other established die systems

Direct extrusion is not limited to solid products, nor is it equivalent to single-action extrusion. Whether a specific hollow section can be produced depends on the die, material, equipment capability and process conditions.

• Mature process with relatively broad product coverage
• Can be matched with solid dies, porthole dies or other established die systems according to product section
• Relative sliding between billet and container wall affects extrusion force and temperature rise
• Butt is normally retained and handled at the end of extrusion
• Equipment tonnage and configuration cannot be determined solely from product outline dimensions; they must also be evaluated against material flow stress, extrusion ratio, cross-section complexity, die strategy and target cycle rate