Expanded metal is a type of sheet metal which has been cut and stretched to form a regular pattern (often diamond-shaped) of mesh-like material. It is commonly used for fences and grates, and as metallic lath to support plaster or stucco.
Expanded metal is a type of sheet metal which has been cut and stretched to form a regular pattern (often diamond-shaped) of mesh-like material. It is commonly used for fences and grates, and as metallic lath to support plaster or stucco.
Expanded metal is stronger than an equivalent weight of wire mesh such as chicken wire, because the material is flattened, allowing the metal to stay in one piece. The other benefit to expanded metal is that the metal is never completely cut and reconnected, allowing the material to retain its strength. [1]
The inventor and patentee of expanded metal is John French Golding, his first British patent was issued in 1884. He forged partnerships with Hartlepool industrialists Mathew Gray, Christopher Furness and Robert Irving Jr., who together with W.B Close brought the manufacture of expanded metal to Hartlepool. The Expanded Metal Company Limited of Hartlepool, United Kingdom, remains a recognised market leader globally in the manufacture of expanded metal to this day and is one of the largest employers locally.
Some commonly used shapes are circles, squares, and diamonds; diamonds are the most popular shapes because of how well the shape absorbs energy and resists mechanical deformation after installation. Other design considerations are the size and angles of the shapes, which will also affect how well the metal absorbs energy and where the energy is spread throughout the expanded metal. [2]
For the diamond shape, there are at least four different angles that come into account, the two acute and two obtuse angles. [3] The larger the angles, the less strength the shape will have because there would be too much space inside the shape. However, if the angles are too small, strength is lost because the shape is too close together, so there is no space for the structure to hold.
The angle in which the shapes are laid also plays a significant role. If the angle is zero the ends of the shape point to the start and the end of the sheet, making straight lines across the sheet of diamonds. This option provide the most strength when it comes to compressing the sheet on its side. This can even take more pressure than a solid piece of metal because the sheet will compress and spread the pressure throughout the sheet. [3] The other four commonly used angles are 60º, 90º, 90º plus 60º, and 60º plus 90º. A 60º angle puts the diamond diagonal at the start and end to the sheet. A 90º angle makes the diamond vertical to the start and the end of a sheet. [3] The 90º plus 60º and 60º plus 90º angles combine both a 60º angle and a 90º angle; the order of the angles is respective to the order in naming. The expanded metal can be manufactured and supplied as standard mesh or can be flattened by further levelling prices to be smooth surface which allows usage of mesh in more applications such as prisons protection to avoid hurting hands touching the mesh.
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Expanded metal is frequently used to make fences, walkways, and grates, as the material is very durable and strong, unlike lighter and less expensive[ dubious ] wire mesh. The many small openings in the material allow flow through of air, water, and light, while still providing a mechanical barrier to larger objects. Another advantage to using expanded metal as opposed to plain sheet metal is that the exposed edges of the expanded metal provide more traction, which has led to its use in catwalks or drainage covers.
Large quantities of expanded metal are used by the construction industry as metal lath to support materials such as plaster, stucco, or adobe in walls and other structures.
Expanded metal is also used by artists, especially sculptors, who use the material to form complex 3-dimensional surfaces and compound curves which can then be covered with plaster, clay, or other materials. For example, Niki de Saint Phalle made extensive use of expanded metal to support the curved surfaces of large-scale architectural sculptures in her Tarot Garden sculpture garden, in Tuscany, Italy.
A similar material made of stiff sheets of paper or cardboard is used as a low-cost cushioning and packaging material.
In contemporary architecture, expanded metal has been used as an exposed facade or screen material which can be formed into simple or complex decorative shapes. Photographic images may be printed on the surface, producing textures or large graphic images, which still allow light to filter through the exterior surface of a building.
Freshly-cut expanded metal has a large number of exposed sharp edges, requiring caution and protective clothing, such as leather gloves and aprons to prevent skin abrasions and cuts.
In metalworking and jewelry making, casting is a process in which a liquid metal is delivered into a mold that contains a negative impression of the intended shape. The metal is poured into the mold through a hollow channel called a sprue. The metal and mold are then cooled, and the metal part is extracted. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods.
A chisel is a tool with a characteristically shaped cutting edge of blade on its end; for carving or cutting a hard material such as wood, stone, or metal by hand, struck with a mallet, or mechanical power. The handle and blade of some types of chisel are made of metal or wood with a sharp edge in it.
Spot welding is a type of electric resistance welding used to weld various sheet metal products, through a process in which contacting metal surface points are joined by the heat obtained from resistance to electric current.
Plaster is a building material used for the protective or decorative coating of walls and ceilings and for moulding and casting decorative elements. In English, "plaster" usually means a material used for the interiors of buildings, while "render" commonly refers to external applications. The term stucco refers to plasterwork that is worked in some way to produce relief decoration, rather than flat surfaces.
Drywall is a panel made of calcium sulfate dihydrate (gypsum), with or without additives, typically extruded between thick sheets of facer and backer paper, used in the construction of interior walls and ceilings. The plaster is mixed with fiber ; plasticizer, foaming agent; and additives that can reduce mildew, flammability, and water absorption.
Facets are flat faces on geometric shapes. The organization of naturally occurring facets was key to early developments in crystallography, since they reflect the underlying symmetry of the crystal structure. Gemstones commonly have facets cut into them in order to improve their appearance by allowing them to reflect light.
Stucco or render is a construction material made of aggregates, a binder, and water. Stucco is applied wet and hardens to a very dense solid. It is used as a decorative coating for walls and ceilings, exterior walls, and as a sculptural and artistic material in architecture. Stucco can be applied on construction materials such as metal, expanded metal lath, concrete, cinder block, or clay brick and adobe for decorative and structural purposes.
Lath and plaster is a building process used to finish mainly interior dividing walls and ceilings. It consists of narrow strips of wood (laths) which are nailed horizontally across the wall studs or ceiling joists and then coated in plaster. The technique derives from an earlier, more primitive process called wattle and daub.
Vacuum forming is a simplified version of thermoforming, where a sheet of plastic is heated to a forming temperature, stretched onto a single-surface mould, and forced against the mould by a vacuum. This process can be used to form plastic into permanent objects such as turnpike signs and protective covers. Normally draft angles are present in the design of the mould to ease removal of the formed plastic part from the mould.
Ferrocement or ferro-cement is a system of construction using reinforced mortar or plaster applied over an "armature" of metal mesh, woven, expanded metal, or metal-fibers, and closely spaced thin steel rods such as rebar. The metal commonly used is iron or some type of steel, and the mesh is made with wire with a diameter between 0.5 mm and 1 mm. The cement is typically a very rich mix of sand and cement in a 3:1 ratio; when used for making boards, no gravel is used, so that the material is not concrete.
Sheet metal is metal formed into thin, flat pieces, usually by an industrial process.
Shot peening is a cold working process used to produce a compressive residual stress layer and modify the mechanical properties of metals and composites. It entails striking a surface with shot with force sufficient to create plastic deformation.
Grinding wheels are wheels that contain abrasive compounds for grinding and abrasive machining operations. Such wheels are also used in grinding machines.
A lath or slat is a thin, narrow strip of straight-grained wood used under roof shingles or tiles, on lath and plaster walls and ceilings to hold plaster, and in lattice and trellis work.
Plasterwork is construction or ornamentation done with plaster, such as a layer of plaster on an interior or exterior wall structure, or plaster decorative moldings on ceilings or walls. This is also sometimes called pargeting. The process of creating plasterwork, called plastering or rendering, has been used in building construction for centuries. For the art history of three-dimensional plaster, see stucco.
A plasterer is a tradesman or tradesperson who works with plaster, such as forming a layer of plaster on an interior wall or plaster decorative moldings on ceilings or walls. The process of creating plasterwork, called plastering, has been used in building construction for centuries. A plasterer is someone who does a full 4 or 2 years apprenticeship to be fully qualified.
This glossary of woodworking lists a number of specialized terms and concepts used in woodworking, carpentry, and related disciplines.
Mechanical screening, often just called screening, is the practice of taking granulated or crushed ore material and separating it into multiple grades by particle size.
Plaster mold casting is a metalworking casting process similar to sand casting except the molding material is plaster of Paris instead of sand. Like sand casting, plaster mold casting is an expendable mold process, however it can only be used with non-ferrous materials. It is used for castings as small as 30 g (1 oz) to as large as 7–10 kg (15–22 lb). Generally, the form takes less than a week to prepare. Production rates of 1–10 units/hr can be achieved with plaster molds.
There are many types of shears used to shear or cut sheet metal.