Forming, metal forming, is the

metalworking Metalworking is the process of shaping and reshaping metals to create useful objects, parts, assemblies, and large scale structures. As a term it covers a wide and diverse range of processes, skills, and tools for producing objects on every scale ...

process of fashioning metal parts and objects through mechanical deformation; the workpiece is reshaped without adding or removing material, and its mass remains unchanged. Forming operates on the materials science principle of

plastic deformation In engineering, deformation refers to the change in size or shape of an object. ''Displacements'' are the ''absolute'' change in position of a point on the object. Deflection is the relative change in external displacements on an object. Strai ...

, where the physical shape of a material is permanently deformed.

Characteristics

Metal forming tends to have more uniform characteristics across its subprocesses than its contemporary processes,

cutting Cutting is the separation or opening of a physical object, into two or more portions, through the application of an acutely directed force. Implements commonly used for cutting are the knife and saw, or in medicine and science the scalpel and ...

and joining. On the industrial scale, forming is characterized by: * Very high loads and stresses required, between 50 and () * Large, heavy, and expensive machinery in order to accommodate such high stresses and loads * Production runs with many parts, to maximize the economy of production and compensate for the expense of the machine tools

Forming processes

Forming processes tend to be categorised by differences in effective stresses. These categories and descriptions are highly simplified, since the stresses operating at a local level in any given process are very complex and may involve many varieties of stresses operating simultaneously, or it may involve stresses which change over the course of the operation. Compressive forming involves those processes where the primary means of plastic deformation is uni- or multiaxial compressive loading. *

Rolling Rolling is a type of motion that combines rotation (commonly, of an axially symmetric object) and translation of that object with respect to a surface (either one or the other moves), such that, if ideal conditions exist, the two are in contact ...

, where the material is passed through a pair of rollers * Extrusion, where the material is pushed through an orifice * Die forming, where the material is stamped by a press around or onto a die *

Forging Forging is a manufacturing process involving the shaping of metal using localized compressive forces. The blows are delivered with a hammer (often a power hammer) or a die. Forging is often classified according to the temperature at whi ...

, where the material is shaped by localized compressive forces *Indenting, where a tool is pressed into the workpiece

Tensile forming

Tensile forming involves those processes where the primary means of plastic deformation is uni- or multiaxial tensile stress. *Stretching, where a tensile load is applied along the longitudinal axis of the workpiece *Expanding, where the circumference of a hollow body is increased by tangential loading *Recessing, where depressions and holes are formed through tensile loading

Combined tensile and compressive forming

This category of forming processes involves those operations where the primary means of plastic deformation involves both tensile stresses and compressive loads. *Pulling through a die * Tandem rolling mill * Deep drawing *

Spinning Spin or spinning most often refers to: * Spinning (textiles), the creation of yarn or thread by twisting fibers together, traditionally by hand spinning * Spin, the rotation of an object around a central axis * Spin (propaganda), an intentionally b ...

Flange A flange is a protruded ridge, lip or rim (wheel), rim, either external or internal, that serves to increase shear strength, strength (as the flange of an iron beam (structure), beam such as an I-beam or a T-beam); for easy attachment/transfer of ...

forming *Upset bulging

Bending

This category of forming processes involves those operations where the primary means of plastic deformation is a bending load.

Shearing

This category of forming processes involves those operations where the primary means of plastic deformation is a shearing load.

Characteristics

Forming processes

Tensile forming

Combined tensile and compressive forming

Bending

Shearing

Notes

References

See also