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,

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 upright=1.35, Sheets of sandpaper with different grit sizes (40 (coarse), 80, 150, 240, 600 (fine)). Sandpaper and glasspaper are names used for a type of coated abrasive that consists of sheets of paper or cloth with abrasive material glued ...

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 ...

-like waste (such as is produced within pipe during pipefitting work); or

stone In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its Chemical compound, chemical composition, and the way in which it is formed. Rocks ...

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 ''Moby-Dick; or, The Whale'' is an 1851 novel by American writer Herman Melville. The book is the sailor Ishmael's narrative of the obsessive quest of Ahab, captain of the whaling ship ''Pequod'', for revenge against Moby Dick, the giant white ...

'', by Herman Melville. Some of these terms are mass nouns (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'', ...

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 Cutter may refer to: Tools * Bolt cutter * Box cutter, aka Stanley knife, a form of utility knife * Cigar cutter * Cookie cutter * Glass cutter * Meat cutter * Milling cutter * Paper cutter * Side cutter * Cutter, a type of hydraulic rescue to ...

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 te ...

, especially if the swarf is coated with cutting oil. To extinguish swarf fires, a special

fire extinguisher A fire extinguisher is a handheld active fire protection device usually filled with a dry or wet chemical used to extinguish or control small fires, often in emergencies. It is not intended for use on an out-of-control fire, such as one which ha ...

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 form m ...

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 Recycling is the process of converting waste materials into new materials and objects. The recovery of energy from waste materials is often included in this concept. The recyclability of a material depends on its ability to reacquire the p ...

References

{{Authority control Machining Metalworking terminology