Forging

Forging is a metal shaping process in which a heated work piece is formed by rapid closing of a punch and a die forcing the work piece to conform to a die cavity.

A work piece may be forged by a series of punch and die operations (or by several cavities in the same die) to gradually change its shape.

The hot metal to be shaped is placed on a die. Impact of a ram on the work piece compels the hot and malleable metal to conform to the shape of a punch and die cavity. Flash at the seam of the punch and die acts as a relief valve for the extreme pressure produced by the closing die halves. Flashing is removed after forming.

Possible shapes

A wide variety of 3D shapes, usually without side holes or recesses.

Forging Design Guidelines

• Avoid undercuts.
• Recommended external draft: 6 degrees (96).
• Recommended internal draft: 8-10 degrees (98-100).
• Provide generous fillet and corner radii to aid material flow.
• Provide support webs and ribs.

Example Forging parts

Connecting rods, crankshafts, wrenches, hooks etc.

Advantages of Forging

Low cost for moderate to long runs.

Specifications for Forging

• Material - Metals with good ductility: aluminum, copper, nickel, mild steel, stainless steel, magnesium.
• Alternative machines - Mill 3-Axis, Casting.
• Tooling - custom tooling in the shape of the part.
• Reducing costs - Minimize size, complexity and material volume.

Forging Notes

Produces a parting line on the work piece - location where the lower and upper die (punch and die) meet. May require machining to obtain dimensional tolerances and good surface finish.