Which term best describes the action of shaping a material using external force such as molding, forging, or rolling?

• A. Casting
• B. Machining
• C. Sintering
• D. Forming

Answer: (D)

Shaping a material by plastically deforming it with external forces is called forming. This umbrella covers processes like forging, rolling, bending, and similar methods, where the material stays solid and its shape is changed through applied pressure or other forces. Forging uses high pressure to squeeze metal into the desired form, while rolling passes the material between rollers to reduce thickness or alter cross-section. Molding fits here as well when the material is pressed into a mold to take on a specific shape. Casting, in contrast, involves pouring liquid material into a mold and letting it solidify, which is not deformation of a solid part. Machining removes material to create the shape, and sintering densifies powders with heat rather than shaping by deforming a solid. So, the best term for shaping by external force like molding, forging, or rolling is forming.