Upset forging is a forging process that increases the diameter of a workpiece like wire or rod by compressing its length using high-speed machines, with standard machines using split dies containing multiple cavities. The process involves the dies opening to move the workpiece between cavities, then closing as a ram moves against the workpiece to upset it into the cavity shape, allowing finished parts to be produced on each cycle for mass production of items like engine valves, bolts, and screws.

1. Upset
forging

2. Upset forging is the forging process
where it increases the diameter of the
work piece by compressing its length.

3. Finish products of Upset Forging
Engine valves

4. Bolts

5. Screws

7. - usually done in special high-speed machines called crank presses
- The initial workpiece is usually wire or rod but some machines can
accept bars up to 25 cm (9.8 in) in diameter and a capacity of over
1000 tons.
- standard upsetting machine employs split dies that contain multiple
cavities

8. Process
• The dies open enough to allow the work piece to move from one
cavity to the next.
• the dies then close and the heading tool, or ram, then moves
longitudinally against the bar, upsetting it into the cavity
• If all of the cavities are utilized on every cycle, then a finished part will
be produced with every cycle, which makes this process
advantageous for mass production.