Glossary

Active Flux

Flux that contains small amounts of deoxidizers to provide improved resistance to porosity and cracking.

Adhesion

Adhesion is the tendency of dissimilar particles or surfaces to cling to one another. The interfacial region where metal atoms come into contact with the film surface may be simply classified as mechanical, diffusion, chemical, and combinations of these types. The type of interfacial region formed depends upon substrate morphology, contamination on the surface, chemical interactions, the energy available during interface formation and the nucleation behavior of the deposited metal.
When the metal atoms strike the surface during deposition, they lose energy to the surface and condense on the surface. During the condensation, the atoms have some degree of mobility on the surface defined by their kinetic energy and the strength and type of interaction between the atoms, clusters of atoms and the substrate surface.

Aging of Metals

The change in the mechanical, physical, and chemical properties of metals and alloys resulting from the lack of thermodynamic equilibrium in the original state and the gradual approach of the structure to the equilibrium state under conditions that permit a sufficient diffusion rate for the atoms. Upon rapid cooling from high temperatures (in hardening or after crystallization and hot working), metals and alloys retain either partially or completely the atomic structure characteristic of the high-temperature state. In pure metals, the irregularity of this structure consists in an excess concentration of vacancies (for low temperatures) and the presence of other defects of the crystal structure. In alloys, the disequilibrium of the structure may be related to the retention of phases that are unstable at low temperatures. Of greatest importance is the aging of alloys, which is caused by the decomposition of a supersaturated solid solution. The state of supersaturation in a solid solution arises after the cooling of alloys from high temperatures inasmuch as the solubility of admixtures or of specially introduced alloying elements usually increases with temperature.

Air Acetylene Welding

Air acetylene welding is one type of gas welding process, where unit body is produced by the heating work piece. The heat is produced from mixture of acetylene and air. Weld joint is made without the application of pressure and with or without use of filler metal.

Alloy Steel

Alloy steel is steel that is alloyed with a variety of elements in total amounts between 1.0% and 50% by weight to improve its mechanical properties. Alloy steels are broken down into two groups: low-alloy steels and high-alloy steels. Most commonly, the phrase "alloy steel" refers to low-alloy steels.
Every steel is truly an alloy, but not all steels are called "alloy steels". Even the simplest steels are iron (Fe) (about 99%) alloyed with carbon (C) (about 0.1% to 1%, depending on type). Common alloyants include manganese (the most common one), nickel, chromium, molybdenum, vanadium, silicon, and boron. Less common alloyants include aluminum, cobalt, copper, cerium, niobium, titanium, tungsten, tin, zinc, lead, and zirconium.
The following is a range of improved properties in alloy steels (as compared to carbon steels): strength, hardness, toughness, wear resistance, corrosion resistance hardenability, and hot hardness. To achieve some of these improved properties the metal may require heat treating.

Anchor Bolt

Anchor bolts are used to attach objects or structures to concrete. There are many types of anchor bolts, consisting of designs that are mostly proprietary to the manufacturing companies. All consist of a threaded end, to which a nut and washer can be attached for the external load. Anchor bolts are extensively used on all types of projects, from standard buildings to dams and nuclear power plants. They can also be used to firmly affix embed plates to a concrete foundation when used with a structural steel element.

Annealing

Annealing is a heat treatment that alters a material to increase its ductility and to make it more workable. It involves heating material to above its critical temperature, maintaining a suitable temperature, and then cooling. Annealing can induce ductility, soften material, relieve internal stresses, refine the structure by making it homogeneous, and improve cold working properties.
In the cases of copper, steel, silver, and brass, this process is performed by heating the material (generally until glowing) for a while and then letting it cool to room temperature in still air. Copper, silver and brass can be cooled slowly in air, or quickly by quenching in water, unlike ferrous metals, such as steel, which must be cooled slowly to anneal. In this fashion, the metal is softened and prepared for further work—such as shaping, stamping, or forming.

Arc Gouging

The formation of a bevel or groove by an arc cutting process.

Arc Strike

"Arc strike" is commonly used to describe a mark left on the metal caused by the misplaced arc being started outside the weld area.

Arc Welding

Arc welding is a type of welding that uses a welding power supply to create an electric arc between an electrode and the base material to melt the metals at the welding point. They can use either direct (DC) or alternating (AC) current, and consumable or non-consumable electrodes. The welding region is usually protected by some type of shielding gas, vapor, or slag. Arc welding processes may be manual, semi-automatic, or fully automated.

Automatic Welding

Automatic welding is electric arc welding in which the basic operations of feeding the electrode into the arc and moving the arc along the line of the weld are mechanized. If only the wire feed is mechanized while the arc is moved by hand, the welding is termed semiautomatic. The most frequently used automatic welding device has a fusible wire electrode wound in a coil weighing between 20 and 60 kg which is continuously fed into the arc as it melts. To protect the welding bath from the air and also to deoxidize the metal and its alloyage, the joint is first filled with a thick layer of flux into which the arc is sunk. The flux ensures high quality of the weld metal, eliminates metal spray, and permits a severalfold increase in the welding current and welding speed compared to open arc welding.
An arc is moved along the line of a weld (for instance, on circular seams) by the motion of an automatic welding machine or of the object itself. If the machine is structurally joined with the traveling mechanism, it is called self-propelled, but if it moves directly on the surface of the object or along a light removable track laid on the object, it is then called a welding tractor. Flexible-hose semiautomatic types of machines are very popular. In these the electrode wire is fed from the mechanism along a flexible hose to a holder in the welder’s hand. Instead of a flux, protective gases such as argon or carbon dioxide, and also gaseous mixtures, are used. However, because of metal spraying in this case, the current and the welding speed are lower than when welding under a flux. Automatic welding using a non-fusible tungsten electrode in a protective gas, usually argon, is also known. In addition to a wire with a solid cross section, a so-called power electrode is also filled with iron powder alloyed with flux-forming components.

Backing Bar

A welding aid used to prevent melting through of a joint when preforming, for example, a complete-joint penetration groove weld.

Backstep Welding

Backstep welding is a technique to avoid distortion while welding on thin sheets. In the backstep technique, the general progression of welding may be left to right, but each bead segment is deposited from right to left. As each bead segment is placed, the heated edges expand, which temporarily separates the plates at B. As the heat moves out across the plate to C, expansion along outer edges CD brings the plates back together. This separation is most pronounced as the first bead. With successive beads, the plates expand less and less because of the restraint from the prior welds.

Beam

Beam is a horizontal or inclined structural member spanning a distance between one or more supports, and carrying vertical loads across (transverse to) its longitudinal axis, as a girder, joist, purlin, or rafter. Three basic types of beams are: (1) Simple span, supported at both ends, (2) Continuous, supported at more than two points, and (3) Cantilever, supported at one end with the other end overhanging and free.

Beam of a Variable Cross-Section

A beam can have a variable cross section. In other words, you can create a tapered beam, in which the starting end has one dimension or shape and the terminal end, another. You can also select a different section shape and a different orientation for the beam beginning and end.

Butt Joint

A butt joint is a joinery technique in which two members are joined by simply butting them together. The butt joint is the simplest joint to make since it merely involves cutting the members to the appropriate length and butting them together. It is also the weakest because unless some form of reinforcement is used it relies upon glue alone to hold it together. Because the orientation of the members usually present only end grain to long grain gluing surface, the resulting joint is inherently weak.

Cantilever

A cantilever is a beam anchored at only one end. The beam carries the load to the support where it is forced against by moment and shear stress. Cantilever construction allows for overhanging structures without external bracing. Cantilevers can also be constructed with trusses or slabs.
This is in contrast to a simply supported beam such as those found in a post and lintel system. A simply supported beam is supported at both ends with loads applied between the supports.

Carbon Steel

Carbon steel is steel in which the main interstitial alloying constituent is carbon in the range of 0.12–2.0%. The American Iron and Steel Institute (AISI) defines carbon steel as the following: "Steel is considered to be carbon steel when no minimum content is specified or required for chromium, cobalt, molybdenum, nickel, niobium, titanium, tungsten, vanadium or zirconium, or any other element to be added to obtain a desired alloying effect; when the specified minimum for copper does not exceed 0.40 percent; or when the maximum content specified for any of the following elements does not exceed the percentages noted: manganese 1.65, silicon 0.60, copper 0.60."
The term "carbon steel" may also be used in reference to steel which is not stainless steel; in this use carbon steel may include alloy steels.
As the carbon percentage content rises, steel has the ability to become harder and stronger through heat treating, however it becomes less ductile. Regardless of the heat treatment, a higher carbon content reduces weldability. In carbon steels, the higher carbon content lowers the melting point.

Castellated Beam

A special fabrication technique is applied to wide-flange shapes to produce castellated beams. This technique consists of cutting the web of a wide-flange shape along a corrugated pattern, separating and shifting the upper and lower pieces, and rewelding the two pieces along the middepth of the newly created beam. The result is a beam with depth, strength, and stiffness greater than the original wide-flange shape, but that maintains the same weight per foot as the original wide-flange shape. In addition, the numerous hexagonal openings, or castellations, that are formed in the beam web can accommodate mechanical ductwork, thereby reducing the overall floor depth.
The load capacity of a castellated beam is frequently dictated by the local strength of the web posts and the tee portions above and below the openings. Therefore, these beams are more efficient for supporting uniform loadings than for concentrated loadings. The latter produce web-shear distributions that tend to be less favorable because the perforated web has less capacity than the solid web.

Ceiling

A ceiling is an overhead interior surface that covers the upper limit of a room. It is not generally considered a structural element, but a finished surface concealing the underside of the floor or roof structure above.

Coating

A coating is a covering that is applied to the surface of an object, usually referred to as the substrate. In many cases coatings are applied to improve surface properties of the substrate, such as appearance, adhesion, wetability, corrosion resistance, wear resistance, and scratch resistance. Some new coatings formulated using nanotechnology promise to create long-term surface protection. In other cases, in particular in printing processes and semiconductor device fabrication (where the substrate is a wafer), the coating forms an essential part of the finished product.

Cold Welding

Cold or contact welding is a solid-state welding process in which joining takes place without fusion/heating at the interface of the two parts to be welded. Unlike in the fusion-welding processes, no liquid or molten phase is present in the joint.
Cold welding was first recognized as a general materials phenomenon in the 1940s. It was then discovered that two clean, flat surfaces of similar metal would strongly adhere if brought into contact under vacuum. Newly discovered micro- and nano-scale cold welding has already shown great potential in the latest nanofabrication processes.

Column

Column or pillar in structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below, in other words a column is a compression member. A small wooden or metal support is typically called a post, and supports with a rectangular or other non-round section are usually called piers. For the purpose of wind or earthquake engineering, columns may be designed to resist lateral forces. Other compression members are often termed "columns" because of the similar stress conditions. Columns are frequently used to support beams or arches on which the upper parts of walls or ceilings rest. In architecture, "column" refers to such a structural element that also has certain proportional and decorative features. A column might also be a decorative element not needed for structural purposes; many columns are "engaged", that is to say form part of a wall.

Conductor

In physics and electrical engineering, a conductor is an object or type of material which permits the flow of electric charges in one or more directions. All conductors contain electrical charges, which will move when an electric potential difference (measured in volts) is applied across separate points on the material. This flow of charge (measured in amperes) is what is meant by electric current. In most materials, the direct current is proportional to the voltage (as determined by Ohm's law), provided the temperature remains constant and the material remains in the same shape and state.

Connection

A link between electrical components or pipes.

Continuous Weld

A weld that is continuous along the entire length of the joint.

Crane Runway Beam

An element of crane runway structures, including the crane beams, brake platforms, crane rails and supports, and receiving the dynamic loads from bridge crane carriers.

Creep

The slow, continuous plastic deformation of a solid under the action of a constant load or mechanical stress.

Crossbar

Any transverse bar or piece, such as a bar across a door, or the iron bar or stock which passes through the shank of an anchor.

Defect

Non-conformance of a product with the specified requirements, or non-fulfillment of user expectations (including the safety aspects). Defects are generally classified into four classes: (1) Class-1: very serious, directly causes severe injury or catastrophic loss; (2) Class-2: serious, directly causes significant injury or economic loss; (3) Class-3: major, related to significant problems with respect to intended normal or reasonable use; and (4) Class-4: minor, related to minor problems with intended normal or reasonable use.

Detailed Working Documentation (KMD)

KMD is a set of shop drawings, which are developed by designers of the manufacturer on the basis of KM drawings, taking into account the technological capabilities of the plant. This is the main technical document, which regulates manufacturing of steel structures at the plant and their installation on a site. A set of drawings includes a circuit diagram of starting elements with labels and assembly units, drawings of starting marks. Each drawing contains complete information on each starting mark: profile type, steel grade, weight of 1 detail, number of parts and total weight of all components. All deviations of KMD drawings from KM drawings should be agreed with the developer.

Ductility

Ductility is a solid material's ability to deform under tensile stress; this is often characterized by the material's ability to be stretched into a wire. Malleability, a similar property, is a material's ability to deform under compressive stress; this is often characterized by the material's ability to form a thin sheet by hammering or rolling. Both of these mechanical properties are aspects of plasticity, the extent to which a solid material can be plastically deformed without fracture. Also, these material properties are dependent on temperature and pressure.

Elastic Limit

The greatest stress that can be applied to a material without causing permanent deformation.

EPC

The EPC contractor (EPCC) agrees to deliver EPC, which is an acronym that stands for engineering, procurement and construction. It is a common form of contracting arrangement within the construction industry.

Fillet Welding

Fillet welding refers to the process of joining two pieces of metal together whether they be perpendicular or at an angle. These welds are commonly referred to as Tee joints which are two pieces of metal perpendicular to each other or Lap joints which are two pieces of metal that overlap and are welded at the edges. The weld is aesthetically triangular in shape and may have a concave, flat or convex surface depending on the welder’s technique. Welders use fillet welds when connecting flanges to pipes, welding cross sections of infrastructure, and when fastening metal by bolts isn't strong enough.

Flux-Cored Arc Welding (FCAW or FCA)

Flux-cored arc welding is a semi-automatic or automatic arc welding process. FCAW requires a continuously-fed consumable tubular electrode containing a flux and a constant-voltage or, less commonly, a constant-current welding power supply. An externally supplied shielding gas is sometimes used, but often the flux itself is relied upon to generate the necessary protection from the atmosphere. The process is widely used in construction because of its high welding speed and portability.

Forge Welding

Forge welding is a solid-state welding process that joins two pieces of metal by heating them to a high temperature and then hammering them together. The process is one of the simplest methods of joining metals and has been used since ancient times. Forge welding is versatile, being able to join a host of similar and dissimilar metals.
The temperature required to forge weld is typically 50 to 90 percent of the melting temperature. Steel welds at a lower temperature than iron. The metal may take on a glossy or wet appearance at the welding temperature. Care must be taken to avoid overheating the metal to the point that it gives off sparks from rapid oxidation (burning).

Forging

Forging is a manufacturing process involving the shaping of metal using localized compressive forces. Forging is often classified according to the temperature at which it is performed: "cold", "warm", or "hot" forging. Forged parts can range in weight from less than a kilogram to 580 metric tons. Forged parts usually require further processing to achieve a finished part.

Framing

Framing is a building technique based around vertical structural members, usually called studs, which provide a stable frame to which interior and exterior wall coverings are attached, and covered by a roof made of horizontal ceiling joists and sloping rafters (or pre-fabricated roof trusses).
Modern light-frame structures usually gain strength from rigid panels (plywood and other plywood-like composites such as oriented strand board (OSB) used to form all or part of wall sections) but until recently carpenters employed various forms of diagonal bracing (called wind braces) to stabilize walls.

Fusion Welding

Fusion welding is a generic term for welding processes that rely upon melting to join materials of similar compositions and melting points. Due to the high-temperature phase transitions inherent to these processes, a heat-affected zone is created in the material (although some techniques, like beam welding, often minimize this effect by introducing comparatively little heat into the workpiece).
Contrast with solid-state welding which does not involve melting of materials.

Galvanization

Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. Although galvanization can be done with electrochemical and electrodeposition processes, the most common method in current use is hot-di galvanization, in which steel parts are submerged in a bath of molten zinc. In industry, the term GI stands for galvanized iron, referring to a common galvanized steel used in many applications such as air ducts and trash cans.

Guy Wire

Guy-wire is a tensioned cable designed to add stability to a free-standing structure. One end of the cable is attached to the structure, and the other is anchored to the ground at a distance from the structure's base. The tension in the diagonal guy-wire, combined with the compressional strength of the structure, allows the structure to withstand lateral loads such as wind or the weight of cantilevered structures. They are often installed radially, at equal angles about the structure, in trios and quads. This allows the tension of each guy-wire to offset the others.

Hangar

Hangar is a closed structure to hold aircraft or other large mechanisms in protective storage. Most hangars are built of metal, but other materials such as wood and concrete are also used. Hangars are used for: protection from weather, protection from direct sunlight, maintenance, repair, manufacture, assembly and storage of aircraft on airfields, aircraft carriers and ships.

Hardening and Tempering

Hardening and tempering of steels is a procedure for modifying the metal's characteristics to better suit the job it has to perform. In the case of toolbits it enables them to machine other materials and still retain a sharp cutting edge, whilst in the case of workpieces it can materially alter their wear characteristics and tensile strength. Virtually all steel hardening processes (as applied by the home machinist) involve the inclusion of particular carbon compounds either at the metal's surface or throughout the body of the metal via the application of heat. Some types of steel (certainly all tool steels) have other trace elements such as cobalt and tungsten in addition to carbon which augment the ultimate hardness achieved and the temperature at which they can operate. The hardening, tempering and annealing of such tool steels ('high-speed' steels as they are known) are beyond the scope of the average home workshop and these steels are usually purchased as shaped bits in the ready hardened state.

Hardness

Hardness is a measure of how resistant solid matter is to various kinds of permanent shape change when a force is applied. Macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex; therefore, there are different measurements of hardness: scratch hardness, indentation hardness, and rebound hardness.
Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity.

Heat Treatment

Heating and cooling a metal or alloy to obtain desired properties or conditions.

Hot-blast stove

A retracting device for preheating the incoming air in an iron blast furnace by using heat from the burning gases of the furnace

High-Strength Bolt

Bolts made from high-strength carbon steel or from alloy steel that has been quenched and tempered.

High-Strength Low-Alloy Steel (HSLA)

High-strength low-alloy steel is a type of alloy steel that provides better mechanical properties or greater resistance to corrosion than carbon steel. HSLA steels vary from other steels in that they are not made to meet a specific chemical composition but rather to specific mechanical properties. They have a carbon content between 0.05–0.25% to retain formability and weldability. Other alloying elements include up to 2.0% manganese and small quantities of copper, nickel, niobium, nitrogen, vanadium, chromium, molybdenum, titanium, calcium, rare earth elements, or zirconium. Copper, titanium, vanadium, and niobium are added for strengthening purposes. These elements are intended to alter the microstructure of carbon steels, which is usually a ferrite-pearlite aggregate, to produce a very fine dispersion of alloy carbides in an almost pure ferrite matrix. This eliminates the toughness-reducing effect of a pearlitic volume fraction yet maintains and increases the material's strength by refining the grain size, which in the case of ferrite increases yield strength by 50% for every halving of the mean grain diameter.

Impact Test

A test designed to give information on how a specimen of a known material will respond to a suddenly applied stress, e.g. shock. The test ascertains whether the material is tough or brittle. A notched test piece is normally employed and the two methods in general use are either the Izod or Charpy test. The result is usually reported as the energy in ft.lbs. or KJ. required to fracture the test piece.

Impact Toughness

The impact toughness (AKA Impact strength) of a material can be determined with a Charpy or Izod test. These tests are named after their inventors and were developed in the early 1900’s before fracture mechanics theory was available. Impact properties are not directly used in fracture mechanics calculations, but the economical impact tests continue to be used as a quality control method to assess notch sensitivity and for comparing the relative toughness of engineering materials.

Intermittent Weld

A weld in which the continuity is broken by recurring unwelded spaces.

Junction

Transition layer or boundary between two different materials or between physically different regions in a single material, especially:
a. A connection between conductors or sections of a transmission line.
b. The interface between two different semiconductor regions in a semiconductor device.
c. A mechanical or alloyed contact between different metals or other materials, as in a thermocouple.

Monorail

A monorail is a rail-based transportation system based on a single rail, which acts as its sole support and its guideway. The term is also used variously to describe the beam of the system, or the vehicles traveling on such a beam or track.

Normalizing

Normalizing is a technique used to provide uniformity in grain size and composition throughout an alloy. The term is often used for ferrous alloys that have been austenitised and then cooled in open air. Normalizing not only produces pearlite, but also bainite and sometimes martensite, which gives harder and stronger steel, but with less ductility for the same composition than full annealing.

Oxy-Fuel Welding

Oxy-fuel welding (commonly called oxyacetylene welding, oxy welding, or gas welding) is the process that use fuel gases and oxygen to weld metals. Pure oxygen, instead of air, is used to increase the flame temperature to allow localized melting of the workpiece material (e.g. steel) in a room environment. A common propane/air flame burns at about 2,000 °C (3,630 °F), a propane/oxygen flame burns at about 2,500 °C (4,530 °F), and an acetylene/oxygen flame burns at about 3,500 °C (6,330 °F).
Oxy-fuel is one of the oldest welding processes. Still used in industry, in recent decades it has been less widely utilized in industrial applications as other specifically devised technologies have been adopted. It is still widely used for welding pipes and tubes, as well as repair work. It is also frequently well-suited, and favored, for fabricating some types of metal-based artwork.

Pipe Fitting

Pipe fitting includes valves, condensate extractors and other devices used to regulate the flow of liquid or gas in pipelines.

Pipe Welding

Pipe welding generally refers to a set of professional skills used for the joining of pieces of metal. Welding is one of the most cost-efficient means of joining multiple sections of pipe and involves heating pieces of metal and joining them so that the resulting product becomes a single piece of metal. This task generally requires welders to learn several methods of connecting pipes and to understand the factors that affect the quality of the connections that they intend to make. Many of the individuals who engage in pipe welding are professionals who specialize in this area of metal work, and they are usually certified.

Pressure Vessel

A pressure vessel is a closed container designed to hold gases or liquids at a pressure substantially different from the ambient pressure.
The pressure differential is dangerous and fatal accidents have occurred in the history of pressure vessel development and operation. Consequently, pressure vessel design, manufacture, and operation are regulated by engineering authorities backed by legislation.

Procedure Certification

Confirmation that the seams are made according to a specific procedure in compliance with the specified standards.

Purlin

Purlin (or historically purline, purloyne, purling, perling) is any longitudinal, horizontal, structural member in a roof except a type of framing with what is called a crown plate. In traditional Timber framing there are three basic types of purlin: purlin plate, principal purlin and common purlin.

Quenching

Quenching is the rapid cooling of a workpiece to obtain certain material properties. It prevents low-temperature processes, such as phase transformations, from occurring by only providing a narrow window of time in which the reaction is both thermodynamically favorable and kinetically accessible. For instance, it can reduce crystallinity and thereby increase toughness of both alloys and plastics (produced through polymerization).
In metallurgy, it is most commonly used to harden steel by introducing martensite, in which case the steel must be rapidly cooled through its eutectoid point, the temperature at which austenite becomes unstable. In steel alloyed with metals such as nickel and manganese, the eutectoid temperature becomes much lower, but the kinetic barriers to phase transformation remain the same. This allows quenching to start at a lower temperature, making the process much easier. High speed steel also has added tungsten, which serves to raise kinetic barriers and give the illusion that the material has been cooled more rapidly than it really has. Even cooling such alloys slowly in air has most of the desired effects of quenching.
Extremely rapid cooling can prevent the formation of all crystal structure, resulting in amorphous metal or "metallic glass".

Rolling

In metalworking, rolling is a metal forming process in which metal stock is passed through a pair of rolls. Rolling is classified according to the temperature of the metal rolled. If the temperature of the metal is above its recrystallization temperature, then the process is termed as hot rolling. If the temperature of the metal is below its recrystallization temperature, the process is termed as cold rolling. In terms of usage, hot rolling processes more tonnage than any other manufacturing process, and cold rolling processes the most tonnage out of all cold working processes.

 

Roof Cladding

Roof cladding can also be known as roofing.  Roof cladding is a protective layer that shields a building's interior and structure from exterior weather and climate. Although the exterior cladding, such as siding, protects a building's walls, roof cladding must be able to effectively deter moisture, winds, temperature and sun from harming a structure. Most often, a roof is clad with shingles or rolled roofing, however other systems protect a roof structure, such as metal panels and rubber roofing.

Roof Pitch

In building construction, roof pitch is a numerical measure of the steepness of a roof. Roofs may be functionally flat or "pitched".

Semi-Automatic Welding

An arc-welding method in which the electrode, a long length of small-diameter bare wire, usually in coil form, is positioned and advanced by the operator from a hand-held welding gun which feeds the electrode through the nozzle.

Shell

The walls of an unfinished or gutted building or other structure.

Shielding Gas

Shielding gases are inert or semi-inert gases that are commonly used in several welding processes, most notably gas metal arc welding and gas tungsten arc welding. Their purpose is to protect the weld area from atmospheric gases, such as oxygen, nitrogen, and water vapour. Depending on the materials being welded, these atmospheric gases can reduce the quality of the weld or make the welding more difficult. Other arc welding processes use other methods of protecting the weld from the atmosphere as well – shielded metal arc welding, for example, uses an electrode covered in a flux that produces carbon dioxide when consumed, a semi-inert gas that is an acceptable shielding gas for welding steel.

Shipping Mark

An identifying word, number, or symbol placed on freight to designate the consignee, destination, weight, and related information.

Soldering Iron

A soldering iron is a hand tool used in soldering. It supplies heat to melt the solder so that it can flow into the joint between two workpieces.
A soldering iron is composed of a heated metal tip and an insulated handle. Heating is often achieved electrically, by passing an electric current (supplied through an electrical cord or battery cables) through a resistive heating element. Cordless irons can be heated by combustion of gas stored in a small tank, often using a catalytic heater rather than a flame. Simple irons less commonly used than in the past were simply a large copper bit on a handle, heated in a flame.
Soldering irons are most often used for installation, repairs, and limited production work in electronics assembly. High-volume production lines use other soldering methods. Large irons may be used for soldering joints in sheet metal objects. Less common uses include pyrography (burning designs into wood) and plastic welding.

Span

Span is the distance between two intermediate supports for a structure, e.g. a beam or a bridge. A span can be closed by a solid beam or by a rope. The first kind is used for bridges, the second one for power lines, overhead telecommunication lines, some type of antennas or for aerial tramways.

Specification

A specification (often abbreviated as spec) may refer to an explicit set of requirements to be satisfied by a material, design, product, or service. Should a material, product, or service fail to meet one or more of the applicable specifications, it may be referred to as being out of specification; the abbreviation OOS may also be used. In casual usage, underspec or overspec are used when something is worse or better than specified (compare overengineering), though in general (such as for sizes) there is only a notion of "in spec" or "out of spec", not "better" or "worse". A specification is a type of technical standard.
A technical specification may be developed by any of various kinds of organizations, both public and private. Example organization types include a corporation, a consortium (a small group of corporations), a trade association (an industry-wide group of corporations), a national government (including its military, regulatory agencies, and national laboratories and institutes), a professional association (society), a purpose-made standards organization such as ISO, or vendor-neutral developed generic requirements (Telcordia Technologies).
A Design or Product Specification describes the features of the solutions for the Requirement Specification. Sometimes the term specification is here used in connection with a data sheet (or spec sheet). This may be confusing. A data sheet describes the technical characteristics of an item or product as designed and/or produced.

Steel

Steel is an alloy of iron and other elements, including carbon. When carbon is the primary alloying element, its content in the steel is between 0.002% and 2.1% by weight. The following elements are always present in steel: carbon, manganese, phosphorus, sulfur, silicon, and traces of oxygen, nitrogen and aluminum. Alloying elements intentionally added to modify the characteristics of steel include: manganese, nickel, chromium, molybdenum, boron, titanium, vanadium and niobium.
Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another. Varying the amount of alloying elements and the form of their presence in the steel (solute elements, precipitated phase) controls qualities such as the hardness, ductility, and tensile strength of the resulting steel. Steel with increased carbon content can be made harder and stronger than iron, but such steel is also less ductile than iron.
Alloys with a higher than 2.1% carbon (depending on other element content and possibly on processing) are known as cast iron. Because they are not malleable even when hot, they can be worked only by casting, and they have lower melting point and good castability. Steel is also distinguishable from wrought iron, which can contain a small amount of carbon.

Steel Structure

Steel structure is a structure in which the members are made of steel and are joined by welding, riveting, or bolting. Because of the high strength of steel, these structures are reliable and require less material than other types of structures. Steel structures are distinguished by the diversity of their shapes and by their architectural expressiveness. Fabrication and installation of steel structures are realized through industrial methods. The main disadvantage of steel structures is susceptibility to corrosion, which requires that protective measures, such as the application of special coatings and paints, be taken periodically, thereby increasing service costs.
In modern construction, steel structures are used mainly as supporting members in buildings and larger structures that vary widely in purpose and design. Examples are residential and public buildings (including high-rise buildings), industrial buildings, especially such metallurgical plants as rolling mills and mills using blast furnaces and open-hearth furnaces, storage tanks and gas tanks, communication structures (radio and television towers and antennas), and power-engineering structures (hydroelectric, thermal, and nuclear power plants, transmission lines). Other examples include transportation structures (bridges, overpasses of railways and highways, depots, hangars), oil and gas pipelines (those suspended over large rivers, ravines, and gorges), stadiums, and pavilions.

Straight Arch

An arch with mutually supporting voussoirs that has a straight horizontal extrados and intrados.

Stress Relieving

Low-temperature heating to reduce residual stress.

Structural Steel

Structural steel is steel construction material, a profile, formed with a specific shape or cross section and certain standards of chemical composition and mechanical properties. Structural steel shape, size, composition, strength, storage, etc., is regulated in most industrialized countries.
Structural steel members, such as I-beams, have high second moments of area, which allow them to be very stiff in respect to their cross-sectional area.

Subcontractor

Subcontractor is an individual or in many cases a business that signs a contract to perform part or all of the obligations of another's contract.
A subcontractor is a person who is hired by a general contractor (or prime contractor, or main contractor) to perform a specific task as part of the overall project and is normally paid for services provided to the project by the originating general contractor. While the most common concept of a subcontractor is in building works and civil engineering, the range of opportunities for subcontractor is much wider and it is possible that the greatest number now operate in the information technology and information sectors of business.

Tack Weld

A joint between two pieces of metal made by welding at isolated points.

Tee Joint
Tee joints are used when one part must be joined to the center of another part forming a “T”. Like the other types of weld, there are several ways that this joint can be prepared and welded, each with their own benefits and disadvantages. Most methods of welding tee joints involve welding the two joints between the parts, with either a high or low energy density beam. Like the other weld types, there are fundamental differences in the processes used with these two types of weld.

Toughness

Toughness is the ability of a material to absorb energy and plastically deform without fracturing. One definition of material toughness is the amount of energy per volume that a material can absorb before rupturing. It is also defined as the resistance to fracture of a material when stressed.

Transmission Tower

A transmission tower is a tall structure, usually a steel lattice tower, used to support an overhead power line. They are used in high-voltage AC and DC systems, and come in a wide variety of shapes and sizes. Typical height ranges from 15 to 55 metres (49 to 180 ft). In addition to steel, other materials may be used, including concrete and wood.
There are four major categories of transmission towers: suspension, terminal, tension, and transposition. Some transmission towers combine these basic functions. Transmission towers and their overhead power lines are often considered to be a form of visual pollution. Methods to reduce the visual effect include undergrounding.

Transverse Seam Welding

Making of a seam weld in a direction essentially at right angles to the throat depth of a seam welding machine.

Truss

A truss is a structure comprising one or more triangular units constructed with straight members whose ends are connected at joints referred to as nodes. External forces and reactions to those forces are considered to act only at the nodes and result in forces in the members which are either tensile or compressive forces. Moments (torques) are explicitly excluded because, and only because, all the joints in a truss are treated as revolutes.
A planar truss is one where all the members and nodes lie within a two dimensional plane, while a space truss has members and nodes extending into three dimensions. The top beams in a truss are called top chords and are generally in compression, the bottom beams are called bottom chords and are generally in tension, the interior beams are called webs, and the areas inside the webs are called panels.

Ultimate Tensile Strength (UTS)

Tensile strength (TS) or ultimate strength is the maximum stress that a material can withstand while being stretched or pulled before failing or breaking. Tensile strength is the opposite of compressive strength and the values can be quite different.
Some materials will break sharply, without deforming, in what is called a brittle failure. Others, which are more ductile, including most metals, will stretch some - and for rods or bars, shrink or neck at the point of maximum stress as that area is stretched out.
The UTS is usually found by performing a tensile test and recording the stress versus strain; the highest point of the stress-strain curve is the UTS. It is an intensive property; therefore its value does not depend on the size of the test specimen. However, it is dependent on other factors, such as the preparation of the specimen, the presence or otherwise of surface defects, and the temperature of the test environment and material.

Walling

An upright structure of masonry, wood, plaster, or other building material serving to enclose, divide, or protect an area, especially a vertical construction forming an inner partition or exterior siding of a building.

Weld Cladding

Cladding is a welding procedure that puts weld metal on the surface of the work, as opposed to joining two pieces of material. Generally this is used for corrosion resistance or wear resistance and frequently a different material is used for the clad than for the base metal.

Weld Line

In manufacturing, the Weld line or Knit line or Meld line is the line where two flow fronts meet when there is the inability of two or more flow fronts to "knit" together, or "weld", during the molding process. These lines usually occur around holes or obstructions and cause locally weak areas in the molded part. Knit lines are considered molding defects, and occur when the mold or/and material temperatures are set too low: thus the materials will be cold when they meet, so that they do not bond perfectly. This can cause a weak area in the part which can cause breakage when the part is under stress. There are many Computer Aided Engineering tools that are available that can predict where these areas could occur.

Weldability

Weldability, also known as joinability, of a material refers to its ability to be welded. Many metals and thermoplastics can be welded, but some are easier to weld than others. A material's weldability is used to determine the welding process and to compare the final weld quality to other materials.
Weldability is often hard to define quantitatively, so most standards define it qualitatively. For instance the International Organization for Standardization (ISO) defines weldability in ISO standard 581-1980 as: "Metallic material is considered to be susceptible to welding to an established extent with given processes and for given purposes when welding provides metal integrity by a corresponding technological process for welded parts to meet technical requirements as to their own qualities as well as to their influence on a structure they form." Other welding organizations define it similarly.

Welding

Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material (the weld pool) that cools to become a strong joint, with pressure sometimes used in conjunction with heat, or by itself, to produce the weld. This is in contrast with soldering and brazing, which involve melting a lower-melting-point material between the workpieces to form a bond between them, without melting the workpieces.
Many different energy sources can be used for welding, including a gas flame, an electric arc, a laser, an electron beam, friction, and ultrasound. While often an industrial process, welding may be performed in many different environments, including open air, under water and in outer space. Welding is a potentially hazardous undertaking and precautions are required to avoid burns, electric shock, vision damage, inhalation of poisonous gases and fumes, and exposure to intense ultraviolet radiation.

Welding Polarity

All electrical circuits have a positive and negative pole called polarity. Welding polarity describes the polarity of an electrical current that is produced by a welder at the electrode. Metal electrodes must have the correct polarity, either "straight" or "reverse," to achieve a weld of the correct strength and quality for the given material. Reverse polarity is also called electrode positive, and straight polarity is referred to as electrode negative. A welder should learn the differences in the welding process to determine the correct polarity.

Welding Spatter

Welding spatter is a term used for those tiny balls of molten metal that are created on a welded piece when welding voltage is too low or amperage is too high. It is also known as slag, and can create an unsightly mess on a welded piece.

Welder’s Admission Test

Demonstration of a welder’s ability to weld seams meeting required standards.

 

Working Documentation (KM)

KM is a set of drawings, designed by a design organization. The KM project includes a title page that contains information about loads, steel grades, schematic designs, plans, transverse and longitudinal sections, components of structures, showing conjugation of individual elements and specification of the metal.

 

 

 

 

 

 

end faq

 

 

 

 

 

 

 
Select site language
Rates of exchange
Rates of exchange 13.07.2015
10 російських рублів 3.87 0.03
100 ЄВРО 2451.36 36.26
100 доларів США 2191.65 6.83
News

29.08.2013
As of today 1,200 tons of steel structures for the construction of new safe confinement of the Chernobyl nuclear power plant have been shipped. All terms on the contract are met, no reclamations.

19.08.2013
The modernization of the gas-plasma facility, released in 2011, has been carried out for the purpose of expansion of production capacity.

22.04.2013
Shipment of tanks to Kazakhstan has been completed. The contract has been executed on time and without reclamations from the customer.

All news

2000-2012 results

Rolled Tanks – 87,000 tons
Layer Installed Tanks – 82,000 tons
Steel Structures – 77,700 tons

Site Session Statistics
Content View Hits : 109847
Our Products

Enakiyevo Metallurgical Works (EMZ),... Read more...
Liepaja Fuel Terminal, LatviaOne tank with volume of 3000... Read more...
Azizi Hotak Group Fuel Terminal, Afghanistan 6 tanks... Read more...
Top