Editing Machinist (section)

==Materials commonly encountered by machinists==
The most common materials that machinists make parts from are [[steel]], [[aluminium]], [[brass]], [[copper]], and various [[alloys]] of these materials. Other less common materials such as [[vanadium]], [[zinc]], [[lead]], or [[manganese]] are often used as [[alloying elements]] for the most common materials. Materials that machinists work with occasionally are [[plastics]], [[rubber]], [[glass]], and wood products. Rarely, machinists also work with exotic and [[refractory metals]]. The term exotic metals is a general term describing out of the ordinary, rare or special purpose metals. A synonym might be space-age. A list of exotic metals might include, but is not limited to, [[titanium]], [[beryllium]], vanadium, [[chromium]], [[molybdenum]] and [[tungsten]], as well as special high-temperature metal alloys like [[Inconel]] or [[Hastelloy]] ([[superalloys]]). Very often the meaning of the term suggests the need for specialized handling and/or tooling to machine them effectively.<ref name=":1">{{Cite web|title = Materials and their properties|url = http://homeshopmachinist.blogspot.com/2010/12/materials-and-their-properties.html|website = Home Shop Machinist|date = 2010-12-08|access-date = 2016-02-04|first = Jaakko|last = Fagerlund}}</ref>

While the foregoing were primarily the materials that a machinist would be cutting, the cutters that the machinist uses must be harder and tougher than the materials to be cut. The materials in the cutters a machinist uses are most commonly [[high-speed steel]], [[tungsten carbide]], [[ceramic]]s, [[Borazon]], and [[diamond]].<ref name=":1" />

Machinists usually work to very small [[Engineering tolerance|tolerances]], usually within 0.010" or 0.25&nbsp;mm (more commonly expressed as ±0.005" (Plus or minus five thousandths of an inch) or ±0.13&nbsp;mm), and sometimes at tolerances as low as +/-0.0001" (plus or minus one tenth of a thousandth of an inch – or 0.0025&nbsp;mm) for specialty operations. A machinist deals with all facets of shaping, cutting and some aspects of forming metal, although forming is typically a separate trade. The operations most commonly performed by machinists are [[milling machine|milling]], [[drilling]], [[turning]], and [[Grinding (abrasive cutting)|grinding]]. There are other more specialized operations that a machinist will less frequently be called upon to perform such as [[honing (metalworking)|honing]], [[keyseating]], [[lapping]], and [[polishing]], to name a few.