Alloy steel forging

One made from a steel containing additional alloying elements other than carbon (e.g., Ni, Cr, Mo) to enhance physical and mechanical properties and/or heat-treat response.

Alloy steel forging

One made from a steel containing additional alloying elements other than carbon (e.g., Ni, Cr, Mo) to enhance physical and mechanical properties and/or heat-treat response.

Carbon steel

Steel containing carbon up to about 1.2%, and only residual amounts of other elements except for those added for composition control, with silicon usually limited to 0.60 % and manganese to 1.65%

Closed die forging

The shaping of hot metal completely within the walls or cavities of two dies that come together to enclose the workpiece on all sides.

Counterblow forging

One made by equipment incorporating two opposed rams, which simultaneously strike repeated blows on the workpiece.

Dies (die blocks)

The metal blocks into which forging impressions are machined and from which forgings are produced.

Disc (disk)

"Pancake" shaped forging (flat with a round cross-section); e.g., a blank for gears, rings and flanged hubs.

Drop forging

A forging made in closed or impression dies under a drop or steam hammer.

Finish allowance

The amount of stock left on the surface of the forging to be removed by subsequent machining. Also called "machining allowance" or "forging envelope."


A projecting rim or edge of a part


Metal in excess of that required to fill completely the blocking or finishing forging impression of a set of dies.


The process of working metal to a desired shape by impact or pressure in hammers, forging machines (upsetters), presses, rolls, and related forming equipment.

Forging reduction

Ratio of the cross-sectional areas before and after forging


A machine that applies a sharp blow to the work area through the fall of a ram onto an anvil.

Hammer forging

The mechanical forming of metal by means of a hammer.

Heat treatment

A sequence of controlled heating and cooling operations applied to a solid metal to impart desired properties.

Hot forging

Same as hot working - plastically deforming an alloy at a temperature above its recrystallization point.

Hydraulic press

A forging press with a hydraulically operated ram.

Induction heating

Heating metals by means of an alternating magnetic field.


A casting intended for subsequent rolling, forging, or extrusion.

Insert die

A relatively small die containing part or all of the impression of a forging, and which isfitted to the master die block by means of a key.


A mechanical device for handling an ingot or a billet during forging.

Mechanical press

A forging press with an inertia flywheel, a crank and clutch, or other mechanical device to operate the ram.


Metals or alloys that contain no appreciable quantity of iron; applied to such metals as aluminum, copper, magnesium, and their alloys.

Open die forging

Forging produced by working between flat or simply contoured dies with unrestricted metal flow using repetitive strokes and continuous manipulation of the workpiece

Precision forging

A forging produced to closer tolerances than normally considered standard by the industry.


A machine tool with a stationary bed and a slide or ram that has reciprocating motion at right angles to the bed surface

Shot blasting

A process of cleaning forgings by propelling metal shot at high velocity by air pressure or centrifugal force at the surface of the forgings

Stainless steels

Steels that are corrosion and heat resistant and contain a minimum of 10% to 12% chromium.

Stamp (marking)

An operation performed to identify the particular forgings as specified or requested by the customer.


The permissible deviation from a specification for any design characteristic.


The removal of the excess metal or flash produced during the forging process.

Trimming press

A power press suitable for trimming flash from forgings.

Upset forging

(1) A forging made by upsetting an appropriate length of bar, billet or bloom. (2)