company news about What is the differences between open die forging and closed die forging?

1. Open Die Forging

Definition:

• Also called free forging, where the workpiece is compressed between flat or simple-shaped dies that do not fully enclose the material.

• Metal flows freely outward during deformation.

Process:

• The workpiece is hammered/pressed repeatedly, with operators repositioning it to achieve the desired shape.

• Minimal tooling constraints; relies on skilled manual control.

Key Features:
✔ Low precision (requires secondary machining).
✔ Improves material properties (grain structure, strength, fatigue resistance).
✔ Flexible for large, heavy parts (e.g., shafts, rings, cylinders).
✔ Lower tooling costs (no complex dies).

Applications:

• Turbine shafts, ship components, large industrial rolls, nuclear/reactor parts.

2. Closed Die Forging

Definition:

• Also called impression die forging, where the workpiece is compressed between two dies with a pre-cut cavity that fully encloses the metal.

• Material flows into the die’s shape, filling the mold completely.

Process:

• High-pressure forces metal into the die’s contours in a single or multiple steps (blocker/finisher dies).

• Flash (excess material) forms around the edges and is trimmed later.

Key Features:
✔ High precision (near-net shape, minimal machining needed).
✔ Excellent surface finish and dimensional consistency.
✔ Higher tooling costs (custom dies required).
✔ Mass production-friendly (e.g., automotive, aerospace fasteners).

Applications:

• Engine crankshafts, gears, connecting rods, aerospace structural parts.

Key Differences Summary

When to Choose Which?

• Open die: Best for large, heavy parts where structural integrity matters more than precision (e.g., oil & gas pipelines).

• Closed die: Ideal for complex, high-tolerance components (e.g., automotive transmissions).