Where does forge collide?

In metalworking, to forge is to shape metal by localized compressive force (hammer blows or press strokes), usually with the work heated into a plastic range, so that the grain flow is refined and aligned to the part's contours. Open-die and closed-die forging produce components prized for toughness and fatigue strength precisely because the deformation consolidates the metal rather than cutting through its fibre. Dieter's Mechanical metallurgy and Kalpakjian and Schmid treat the mechanics, temperature–strain-rate windows, and die design of the process. The referent is a deformation process for metal, and it shares only the spelling with the act of faking a document.[1][2]

Unit

The forging load and deformation that shape the workpiece

Recovery means

Not applicable

Measured by

Characterised by forging load, die fill, grain flow, and the temperature and strain-rate window of hot working

In forensic science, to forge is to fraudulently make or imitate a writing, signature, or document so as to pass it off as genuine, and forgery is the examiner's object of study: distinguishing an authentic hand from a simulated one. Forgers trade fluency for accuracy, so forged signatures tend to show tremor, pen lifts, and hesitation absent from genuine writing, while a writer disguising their own hand shows a different signature pattern again. Dyer, Found, and Rogers tested how reliably document examiners separate genuine, forged, and disguised signatures. The referent is an act of deceptive imitation judged against an authentic exemplar, entirely unlike compressing hot steel, though both are called forging.[3]

Unit

The deviation of an imitated writing from a genuine exemplar

Recovery means

Not applicable

Measured by

Assessed by examiner agreement and error rates in discriminating genuine, forged, and disguised signatures