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 manufacturing process where a desired shape or part is created using the controlled removal of material, most often metal, from a larger piece of raw material by cutting. Machining is a form of subtractive manufacturing, which util ...

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

, or similar subtractive (material-removing)

manufacturing Manufacturing is the creation or production of goods with the help of equipment, labor, machines, tools, and chemical or biological processing or formulation. It is the essence of the secondary sector of the economy. The term may refer ...

processes. Swarf can be small

particles In the physical sciences, a particle (or corpuscle in older texts) is a small localized object which can be described by several physical or chemical properties, such as volume, density, or mass. They vary greatly in size or quantity, from s ...

(such as the gritty swarf from grinding metal or the sawdust from sawing or

sanding file:Schleifpapier verschiedene Sorten.jpg, upright=1.35, Sheets of sandpaper with different grit sizes (40 (coarse), 80, 150, 240, 600 (fine)) Sandpaper, also known as coated abrasive or emery paper, is a type of material that consists of sheet ...

wood); long, stringy tendrils (such as the springy chips from turning tough metals, or long shavings from whittling);

slag The general term slag may be a by-product or co-product of smelting (pyrometallurgical) ores and recycled metals depending on the type of material being produced. Slag is mainly a mixture of metal oxides and silicon dioxide. Broadly, it can be c ...

-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 Dust is made of particle size, fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian processes, aeolian process), Types of volcan ...

(as in

masonry Masonry is the craft of building a structure with brick, stone, or similar material, including mortar plastering which are often laid in, bound, and pasted together by mortar (masonry), mortar. The term ''masonry'' can also refer to the buildin ...

)."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 Epic (genre), epic novel by American writer Herman Melville. The book is centered on the sailor Ishmael (Moby-Dick), Ishmael's narrative of the maniacal quest of Captain Ahab, Ahab, captain of the whaler ...

'', 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 eleme ...

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 Injury is physiological damage to the living tissue of any organism, whether in humans, in other animals, or in plants. Injuries can be caused in many ways, including mechanically with penetration by sharp objects such as teeth or with b ...

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 (symbol ''A'') 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 d ...

, swarf composed of some reactive metals can be highly flammable. Swarf may also spontaneously combust, 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 A coolant is a substance, typically liquid, that is used to reduce or regulate the temperature of a system. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, chemically inert and neither causes nor promotes corr ...

, swarf is usually very hot and can easily burn the machine operator. Machinists typically wear long pants, eye protection and other

personal protective equipment Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, elect ...

for this reason. Some engineering materials such as

beryllium Beryllium is a chemical element; it has Symbol (chemistry), symbol Be and atomic number 4. It is a steel-gray, hard, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with ...

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. This concept often includes the recovery of energy from waste materials. The recyclability of a material depends on its ability to reacquire the propert ...

References

{{Authority control Machining Metalworking terminology

Metal swarf

See also

References