1. Upsetting Press

The machine cycle of an upsetting press relies on the mechanical synchronization of the clamping and heading slides.

Phase 1: Preparation and Gauging

1. Selective Heating: The workpiece (bar stock) is heated locally (induction or gas) only at the section to be deformed.
2. Stock Gauging: The heated bar is inserted into the stationary die until it contacts the Stock Stop. This ensures the correct "Upset Volume" for the heading tool.

Phase 2: The Mechanical Cycle

1. Clamping (Grip): Upon triggering, the Grip Slide closes. It exerts a clamping force ($F_c$) to lock the bar against the stationary die.
2. The Heading Blow: The Main Slide advances. The heading tool impacts the heated end, forcing the metal to fill the die cavity through plastic flow.

Phase 3: Extraction

1. Tool Retraction: The heading slide retracts first to prevent the part from sticking.
2. Die Opening: The grip slide opens.
3. Ejection: An integrated "kick-out" pin or mechanical ejector pushes the finished part from the die cavity for retrieval.

2. Extrusion Press

The extrusion procedure is a high-pressure hydraulic displacement cycle focusing on "steady-state" flow.

Phase 1: Billet Loading and Sealing

1. Billet Delivery: The heated billet (log) is placed in the press cradle by a mechanical loader.
2. Container Sealing: The main ram pushes the billet into the Container. The container then shifts forward to form a high-pressure seal against the Die Bolster.
3. The Burp (De-gassing): A momentary pause in ram pressure allows air trapped between the billet and container to escape, preventing internal defects.

Phase 2: The Extrusion Stroke

1. Breakout: Hydraulic pressure is increased until the metal overcomes static friction and begins flowing through the die.
2. The Push: The ram maintains a controlled velocity. In Isothermal Extrusion, the speed is adjusted to compensate for friction-generated heat.
3. The Discard: The stroke stops before the ram reaches the die, leaving a "butt" (discard) containing the oxides and impurities from the billet skin.

Phase 3: Post-Processing

1. Shearing: The container retracts, and a vertical hydraulic shear cuts the finished profile away from the discard at the die face.
2. Stretching: The profile is pulled on a stretching table to remove longitudinal waves and relieve internal stresses.