Swarf, also known as chips or by other process-specific names (such as turnings, filings, or shavings), are pieces of metal, wood, or plastic that are the debris or waste resulting from

machining Machining is a process in which a material (often metal) is cut to a desired final shape and size by a controlled material-removal process. The processes that have this common theme are collectively called subtractive manufacturing, which utilizes ...

woodworking Woodworking is the skill of making items from wood, and includes cabinet making (cabinetry and furniture), wood carving, joinery, carpentry, and woodturning. History Along with stone, clay and animal parts, wood was one of the first mate ...

, or similar subtractive (material-removing) manufacturing processes. Swarf or chips can be small particles (such as the gritty swarf from grinding metal or the sawdust from sawing or sanding wood); long, stringy tendrils (such as the springy chips from

turning Turning is a machining process in which a cutting tool, typically a non-rotary tool bit, describes a helix toolpath by moving more or less linearly while the workpiece rotates. Usually the term "turning" is reserved for the generation ...

tough Tough may refer to: * Toughness, the resistance to fracture of a material when stressed * Machismo, prominently exhibited or excessive masculinity * Psychological resilience Tough may also refer to: People * Allen Tough (1936–2012), Canadian ...

metals, or long shavings from whittling);

slag Slag is a by-product of smelting ( pyrometallurgical) ores and used metals. Broadly, it can be classified as ferrous (by-products of processing iron and steel), ferroalloy (by-product of ferroalloy production) or non-ferrous/base metals (by-p ...

-like waste (such as is produced within pipe during pipefitting work); or stone fragments and dust (as in

masonry Masonry is the building of structures from individual units, which are often laid in and bound together by mortar; the term ''masonry'' can also refer to the units themselves. The common materials of masonry construction are bricks, building ...

)."The universe is finished; the copestone is on, and the chips were carted off a million years ago." —Ishmael, in '' Moby-Dick'', by Herman Melville. Some of these terms are

mass noun In linguistics, a mass noun, uncountable noun, non-count noun, uncount noun, or just uncountable, is a noun with the syntactic property that any quantity of it is treated as an undifferentiated unit, rather than as something with discrete elemen ...

s (such as ''swarf'' and ''sawdust'') and some of them are

count noun In linguistics, a count noun (also countable noun) is a noun that can be modified by a quantity and that occurs in both singular and plural forms, and that can co-occur with quantificational determiners like ''every'', ''each'', ''several'', e ...

s (such as ''chips'', ''filings'', or ''shavings''). Wood swarf is discussed at '' sawdust''.

Metal swarf

Chips can be extremely sharp and they can cause serious injuries if not handled correctly. It is not uncommon for chips flying off the cutter to be ejected with great force and to fly several yards. Due to its high

surface area The surface area of a solid object is a measure of the total area that the surface of the object occupies. The mathematical definition of surface area in the presence of curved surfaces is considerably more involved than the definition of ...

, swarf composed of some reactive metals can be highly flammable. Swarf may also

spontaneously combust Spontaneous combustion or spontaneous ignition is a type of combustion which occurs by self-heating (increase in temperature due to exothermic internal reactions), followed by thermal runaway (self heating which rapidly accelerates to high tem ...

, especially if the swarf is coated with cutting oil. To extinguish swarf fires, a special fire extinguisher is needed, designed for fighting Class D (metal) fires. When machining without coolant, swarf is usually very hot and can easily burn the machine operator. Machinists typically wear long pants, eye protection and other personal protective equipment for this reason. Some common engineering materials such as

beryllium Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to for ...

are hazardous when finely divided and appropriate measures should be taken to prevent exposure. For ease of transport and handling, swarf may be compressed into ''bricks''. Metal swarf can usually be recycled.

References

{{Authority control Machining Metalworking terminology