Compare Forging Process to Machined Steel Bar / Plate

Compare and contrast machined steel bar and plate to forging – in terms of size range, grain orientation strength, use of materials, scrap and production, and requirement for secondary operations.

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Machined Steel Bar/Plate

Forging

Size range of desired material grades: Sizes and shapes of products made from steel bar and plate are limited to the dimensions in which these materials are supplied. Forging is often the only metalworking option available with certain grades in desired sizes. Forgings can be economically produced in a wide range of sizes - from parts whose largest dimension is less than 1 in. to parts weighing more than 450,000 lbs.
Strength of grain orientation: Machined bar and plate is more susceptible to fatigue and stress corrosion because machining cuts material grain pattern. Forging yields a grain structure oriented to the part shape, resulting in optimum strength, ductility and resistance to impact and fatigue.
 Economical use of materials: Flame cutting plate is a wasteful process - one of several fabricating steps that consumes more material than needed to make parts such as rings or hubs. Even more is lost in subsequent machining. Material cost savings can be significant, whether aluminum, steel or special alloy forging is applied.
Rate of scrap and cost-effectiveness of production: Because of the inherent waste to the steel bar and plate machining process, there is always a high rate of scrap and loss in cost. Better use of material, especially for near net shape forgings, generates little scrap. In high-volume production runs, forgings have the decisive cost advantage.
Requirement for secondary operations: Some grades of bar and plate require additional operations - such as turning, grinding and polishing - to remove surface irregularities and achieve the desired finish, machinability, dimensional accuracy and strength. On average, forgings can be put into service without expensive secondary operations.


For more information on forgings compared to machined bar / plate, visit the Forging Industry Association (FIA) website.