Metalworking

Metalworking is the process of shaping and reshaping metals in order 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: from huge ships, buildings, and bridges, down to precise engine parts and delicate jewelry.

The historical roots of metalworking predate recorded history; its use spans cultures, civilizations and millennia.

[2] The earliest substantiated and dated evidence of metalworking in the Americas was the processing of copper in Wisconsin, near Lake Michigan.

Another feature of gold is that it is workable as it is found, meaning that no technology beyond a stone hammer and anvil is needed to work the metal.

[6] The end of the beginning of metalworking occurs sometime around 6000 BCE when copper smelting became common in Southwestern Asia.

About 2700 BCE, production of bronze was common in locales where the necessary materials could be assembled for smelting, heating, and working the metal.

[citation needed] By the historical periods of the Pharaohs in Egypt, the Vedic Kings in India, the Tribes of Israel, and the Maya civilization in North America, among other ancient populations, precious metals began to have value attached to them.

For example, the granulation technique was employed by numerous ancient cultures before the historic record shows people traveled to far regions to share this process.

Skills related to extracting metal ores from the earth began to evolve, and metalsmiths became more knowledgeable.

The metalworker depends on the extraction of precious metals to make jewelry, build more efficient electronics, and for industrial and technological applications from construction to shipping containers to rail, and air transport.

In the metal trades area, marking out consists of transferring the engineer's plan to the workpiece in preparation for the next step, machining or manufacture.

Casting achieves a specific form by pouring molten metal into a mold and allowing it to cool, with no mechanical force.

Advancements in automated metalworking technology have made progressive die stamping possible which is a method that can encompass punching, coining, bending and several other ways below that modify metal at less cost while resulting in less scrap.

The use of an angle grinder in cutting is not preferred as large amounts of harmful sparks and fumes (and particulates) are generated when compared with using reciprocating saw or band saw.

The pieces produced are usually complex 3D objects that are converted into x, y, and z coordinates that are then fed into the CNC machine and allow it to complete the tasks required.

The milling machine can produce most parts in 3D, but some require the objects to be rotated around the x, y, or z coordinate axis (depending on the need).

Turning is a metal cutting process for producing a cylindrical surface with a single point tool.

Examples of objects that can be produced on a lathe include candlestick holders, crankshafts, camshafts, and bearing mounts.

Other operations that can be performed with a single point tool on a lathe are:[13] Chamfering: Cutting an angle on the corner of a cylinder.

Boring: A single-point tool is fed linearly and parallel to the axis of rotation to create a round hole.

From the old days of a manual toolroom grinder sharpening endmills for a production shop, to today's 30000 RPM CNC auto-loading manufacturing cell producing jet turbines, grinding processes vary greatly.

Prior to the development of modern machining equipment it provided a relatively accurate means for the production of small parts, especially those with flat surfaces.

[14] Many different energy sources can be used for welding, including a gas flame, an electric arc, a laser, an electron beam, friction, and ultrasound.

Regardless of location, however, welding remains dangerous, and precautions must be taken to avoid burns, electric shock, poisonous fumes, and overexposure to ultraviolet light.

Brazing is a joining process in which a filler metal is melted and drawn into a capillary formed by the assembly of two or more work pieces.

It is similar to brazing in the way that a filler is melted and drawn into a capillary to form a joint, although at a lower temperature.

Metals can be heat treated to alter the properties of strength, ductility, toughness, hardness or resistance to corrosion.

It involves bonding a thin layer of another metal such as gold, silver, chromium or zinc to the surface of the product by hydrolysis.

Plating can even change the properties of the original part including conductivity, heat dissipation or structural integrity.