Fabrication (metal)
Overview
Fabrication as an industrial term refers to building metal structures by cutting, bending, and assembling. The cutting part of fabrication is via saw
Saw
A saw is a tool that uses a hard blade or wire with an abrasive edge to cut through softer materials. The cutting edge of a saw is either a serrated blade or an abrasive...

ing, shearing
Shear (sheet metal)
-Bench shear:A bench shear, also known as a lever shear, is a bench mounted shear with a compound mechanism to increase the mechanical advantage. It is usually used for cutting rough shapes out of medium sized pieces of sheet metal, but cannot do delicate work. For the small shear, it mostly...

, or chisel
Chisel
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. The handle and blade of some types of chisel are made of metal or wood with a sharp edge in it.In use, the chisel is forced into the material...

ing (all with manual
Hand tool
A hand tool is a device for performing work on a material or a physical system using only hands. The hand tools can be manually used employing force, or electrically powered, using electrical current...

 and powered
Power tool
A power tool is a tool that is actuated by an additional power source and mechanism other than the solely manual labour used with hand tools. The most common types of power tools use electric motors. Internal combustion engines and compressed air are also commonly used...

 variants); torching with handheld torches (such as oxy-fuel torches
Oxy-fuel welding and cutting
Oxy-fuel welding and oxy-fuel cutting are processes that use fuel gases and oxygen to weld and cut metals, respectively. French engineers Edmond Fouché and Charles Picard became the first to develop oxygen-acetylene welding in 1903...

 or plasma torch
Plasma torch
A plasma torch is a device for generating a directed flow of plasma. The plasma jet can be used for applications including plasma cutting, plasma spraying, and plasma arc waste disposal....

es); and via CNC
Numerical control
Numerical control refers to the automation of machine tools that are operated by abstractly programmed commands encoded on a storage medium, as opposed to controlled manually via handwheels or levers, or mechanically automated via cams alone...

 cutters (using a laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...

, torch, or water jet
Water jet cutter
A water jet cutter, also known as a waterjet, is a tool capable of slicing into metal or other materials using a jet of water at high velocity and pressure, or a mixture of water and an abrasive substance. The process is essentially the same as water erosion found in nature but greatly accelerated...

). The bending is via hammer
Hammer
A hammer is a tool meant to deliver an impact to an object. The most common uses are for driving nails, fitting parts, forging metal and breaking up objects. Hammers are often designed for a specific purpose, and vary widely in their shape and structure. The usual features are a handle and a head,...

ing (manual or powered) or via press brakes and similar tools. The assembling (joining of the pieces) is via welding
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 that cools to become a strong joint, with pressure sometimes...

, binding with adhesive
Adhesive
An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...

s, rivet
Rivet
A rivet is a permanent mechanical fastener. Before being installed a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite the head is called the buck-tail. On installation the rivet is placed in a punched or pre-drilled hole, and the tail is upset, or bucked A rivet...

ing, threaded fasteners
Screw
A screw, or bolt, is a type of fastener characterized by a helical ridge, known as an external thread or just thread, wrapped around a cylinder. Some screw threads are designed to mate with a complementary thread, known as an internal thread, often in the form of a nut or an object that has the...

, or even yet more bending in the form of a crimped seam.
Encyclopedia
Fabrication as an industrial term refers to building metal structures by cutting, bending, and assembling. The cutting part of fabrication is via saw
Saw
A saw is a tool that uses a hard blade or wire with an abrasive edge to cut through softer materials. The cutting edge of a saw is either a serrated blade or an abrasive...

ing, shearing
Shear (sheet metal)
-Bench shear:A bench shear, also known as a lever shear, is a bench mounted shear with a compound mechanism to increase the mechanical advantage. It is usually used for cutting rough shapes out of medium sized pieces of sheet metal, but cannot do delicate work. For the small shear, it mostly...

, or chisel
Chisel
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. The handle and blade of some types of chisel are made of metal or wood with a sharp edge in it.In use, the chisel is forced into the material...

ing (all with manual
Hand tool
A hand tool is a device for performing work on a material or a physical system using only hands. The hand tools can be manually used employing force, or electrically powered, using electrical current...

 and powered
Power tool
A power tool is a tool that is actuated by an additional power source and mechanism other than the solely manual labour used with hand tools. The most common types of power tools use electric motors. Internal combustion engines and compressed air are also commonly used...

 variants); torching with handheld torches (such as oxy-fuel torches
Oxy-fuel welding and cutting
Oxy-fuel welding and oxy-fuel cutting are processes that use fuel gases and oxygen to weld and cut metals, respectively. French engineers Edmond Fouché and Charles Picard became the first to develop oxygen-acetylene welding in 1903...

 or plasma torch
Plasma torch
A plasma torch is a device for generating a directed flow of plasma. The plasma jet can be used for applications including plasma cutting, plasma spraying, and plasma arc waste disposal....

es); and via CNC
Numerical control
Numerical control refers to the automation of machine tools that are operated by abstractly programmed commands encoded on a storage medium, as opposed to controlled manually via handwheels or levers, or mechanically automated via cams alone...

 cutters (using a laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...

, torch, or water jet
Water jet cutter
A water jet cutter, also known as a waterjet, is a tool capable of slicing into metal or other materials using a jet of water at high velocity and pressure, or a mixture of water and an abrasive substance. The process is essentially the same as water erosion found in nature but greatly accelerated...

). The bending is via hammer
Hammer
A hammer is a tool meant to deliver an impact to an object. The most common uses are for driving nails, fitting parts, forging metal and breaking up objects. Hammers are often designed for a specific purpose, and vary widely in their shape and structure. The usual features are a handle and a head,...

ing (manual or powered) or via press brakes and similar tools. The assembling (joining of the pieces) is via welding
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 that cools to become a strong joint, with pressure sometimes...

, binding with adhesive
Adhesive
An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...

s, rivet
Rivet
A rivet is a permanent mechanical fastener. Before being installed a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite the head is called the buck-tail. On installation the rivet is placed in a punched or pre-drilled hole, and the tail is upset, or bucked A rivet...

ing, threaded fasteners
Screw
A screw, or bolt, is a type of fastener characterized by a helical ridge, known as an external thread or just thread, wrapped around a cylinder. Some screw threads are designed to mate with a complementary thread, known as an internal thread, often in the form of a nut or an object that has the...

, or even yet more bending in the form of a crimped seam. Structural steel
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...

 and sheet metal
Sheet metal
Sheet metal is simply metal formed into thin and flat pieces. It is one of the fundamental forms used in metalworking, and can be cut and bent into a variety of different shapes. Countless everyday objects are constructed of the material...

 are the usual starting materials for fabrication, along with the welding wire, flux, and fasteners that will join the cut pieces. As with other manufacturing processes, both human labor and automation
Automation
Automation is the use of control systems and information technologies to reduce the need for human work in the production of goods and services. In the scope of industrialization, automation is a step beyond mechanization...

 are commonly used. The product resulting from (the process of) fabrication may be called a fabrication. Shops that specialize in this type of metal work are called fab shops. The end products of other common types of metalworking, such as machining
Machining
Conventional machining is a form of subtractive manufacturing, in which a collection of material-working processes utilizing power-driven machine tools, such as saws, lathes, milling machines, and drill presses, are used with a sharp cutting tool to physical remove material to achieve a desired...

, metal stamping, forging
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...

, and casting
Casting
In metalworking, casting involves pouring liquid metal into a mold, which contains a hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process...

, may be similar in shape and function, but those processes are not classified as fabrication.

Fabrication comprises or overlaps with various metalworking specialties:
  • Fabrication shops and machine shops have overlapping capabilities, but fabrication shops generally concentrate on metal preparation and assembly as described above. By comparison, machine shops also cut metal, but they are more concerned with the machining
    Machining
    Conventional machining is a form of subtractive manufacturing, in which a collection of material-working processes utilizing power-driven machine tools, such as saws, lathes, milling machines, and drill presses, are used with a sharp cutting tool to physical remove material to achieve a desired...

     of parts on machine tool
    Machine tool
    A machine tool is a machine, typically powered other than by human muscle , used to make manufactured parts in various ways that include cutting or certain other kinds of deformation...

    s. Firms that encompass both fab work and machining are also common.
  • Blacksmith
    Blacksmith
    A blacksmith is a person who creates objects from wrought iron or steel by forging the metal; that is, by using tools to hammer, bend, and cut...

    ing has always involved fabrication, although it was not always called by that name.
  • The products produced by welder
    Welder
    A welder is a tradesman who specializes in welding materials together. The materials to be joined can be metals or varieties of plastic or polymer...

    s, which are often referred to as weldments, are an example of fabrication.
  • Boilermaker
    Boilermaker
    A boilermaker is a trained craftsman who produces steel fabrications from plates and sections. The name originated from craftsmen who would fabricate boilers, but they may work on projects as diverse as bridges to blast furnaces to the construction of mining equipment.-Boilermaking:Many...

    s originally specialized in boiler
    Boiler
    A boiler is a closed vessel in which water or other fluid is heated. The heated or vaporized fluid exits the boiler for use in various processes or heating applications.-Materials:...

    s, leading to their trade's name, but the term as used today has a broader meaning.
  • Similarly, millwright
    Millwright
    A millwright is a craftsman or tradesman engaged with the construction and maintenance of machinery.Early millwrights were specialist carpenters who erected machines used in agriculture, food processing and processing lumber and paper...

    s originally specialized in setting up grain mills and saw mills, but today they may be called upon for a broad range of fabrication work.
  • Ironworker
    Ironworker
    Ironworker is a class of machines that can shear, notch, and punch holes in steel plate. Ironworkers generate force using mechanical advantage or hydraulic systems. Modern systems use hydraulic rams powered by a heavy alternating current electric motor. High strength carbon steel blades and dies...

    s, also known as steel erectors, also engage in fabrication. Often the fabrications for structural work begin as prefabricated segments in a fab shop, then are moved to the site by truck
    Truck
    A truck or lorry is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration, with the smallest being mechanically similar to an automobile...

    , rail
    Rail transport
    Rail transport is a means of conveyance of passengers and goods by way of wheeled vehicles running on rail tracks. In contrast to road transport, where vehicles merely run on a prepared surface, rail vehicles are also directionally guided by the tracks they run on...

    , or barge
    Barge
    A barge is a flat-bottomed boat, built mainly for river and canal transport of heavy goods. Some barges are not self-propelled and need to be towed by tugboats or pushed by towboats...

    , and finally are installed by erectors.

Metal fabrication

Metal fabrication is a value added
Value added
In economics, the difference between the sale price and the production cost of a product is the value added per unit. Summing value added per unit over all units sold is total value added. Total value added is equivalent to Revenue less Outside Purchases...

 process that involves the construction of machines and structures from various raw materials. A fab shop will bid on a job, usually based on the engineering drawing
Engineering drawing
An engineering drawing, a type of technical drawing, is used to fully and clearly define requirements for engineered items.Engineering drawing produces engineering drawings . More than just the drawing of pictures, it is also a language—a graphical language that communicates ideas and information...

s, and if awarded the contract will build the product.

Fabrication shops are employed by contractors
General contractor
A general contractor is responsible for the day-to-day oversight of a construction site, management of vendors and trades, and communication of information to involved parties throughout the course of a building project.-Description:...

, OEMs
Original Equipment Manufacturer
An original equipment manufacturer, or OEM, manufactures products or components that are purchased by a company and retailed under that purchasing company's brand name. OEM refers to the company that originally manufactured the product. When referring to automotive parts, OEM designates a...

 and VARs
Value-added reseller
A value-added reseller is a company that adds features or services to an existing product, then resells it as an integrated product or complete "turn-key" solution...

. Typical projects include; loose parts, structural frames for buildings and heavy equipment, and hand railings and stairs for buildings.

Engineering

The fabricator may employ or contract out steel detailer
Steel detailer
A steel detailer is a person who produces detailed drawings for steel fabricators and steel erectors. The detailer prepares detailed plans, drawings and other documents for the manufacture and erection of steel members used in the construction of buildings, bridges, industrial plants, and...

s to prepare shop drawings, if not provided by the customer, which the fabricating shop will use for manufacturing. Manufacturing engineers will program CNC machines as needed.

Raw materials

Standard raw materials used by metal fabricators are;
  • plate metal
  • formed and expanded metal
    Expanded metal
    Expanded metal is a form of metal stock made by shearing a metal plate in a press, so that the metal stretches, leaving diamond-shaped voids surrounded by interlinked bars of the metal. The most common method of manufacture is to simultaneously slit and stretch the material with one motion...

    • tube stock, CDSM
    • square stock
    • sectional metals
      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...

       (I beams, W beams, C-channel...)
  • welding wire
  • hardware
    Hardware
    Hardware is a general term for equipment such as keys, locks, hinges, latches, handles, wire, chains, plumbing supplies, tools, utensils, cutlery and machine parts. Household hardware is typically sold in hardware stores....

  • castings
  • fittings

Cutting and burning

The raw material has to be cut to size. This is done with a variety of tools.

The most common way to cut material is by Shearing (metalworking)
Shearing (metalworking)
Shearing, also known as die cutting, is a process which cuts stock without the formation of chips or the use of burning or melting. Strictly speaking, if the cutting blades are straight the process is called shearing; if the cutting blades are curved then they are shearing-type operations...

;

Special band saw
Band saw
A bandsaw is a power tool which uses a blade consisting of a continuous band of metal with teeth along one edge to cut various workpieces. The band usually rides on two wheels rotating in the same plane, although some small bandsaws have three wheels. Bandsawing produces uniform cutting action as a...

s designed for cutting metal have hardened blades and a feed mechanism for even cutting. Abrasive cut-off saws, also known as chop saws, are similar to miter saws but with a steel cutting abrasive disk. Cutting torches can cut very large sections of steel with little effort.

Burn tables are CNC cutting torches, usually natural gas powered. Plasma and laser cutting
Laser cutting
Laser cutting is a technology that uses a laser to cut materials, and is typically used for industrial manufacturing applications, but is also starting to be used by schools, small businesses and hobbyists. Laser cutting works by directing the output of a high-power laser, by computer, at the...

 tables, and Water jet cutter
Water jet cutter
A water jet cutter, also known as a waterjet, is a tool capable of slicing into metal or other materials using a jet of water at high velocity and pressure, or a mixture of water and an abrasive substance. The process is essentially the same as water erosion found in nature but greatly accelerated...

s, are also common. Plate steel is loaded on a table and the parts are cut out as programmed. The support table is made of a grid of bars that can be replaced. Some very expensive burn tables also include CNC punch capability, with a carousel of different punches and taps. Fabrication of structural steel by plasma and laser cutting introduces robots to move the cutting head in three dimensions around the material to be cut.

Forming

Hydraulic brake press
Brake press
A press brake, also known as a brake press or just brake, is a machine tool for bending sheet and plate material, most commonly sheet metal....

es with v-dies are the most common method of forming metal. The cut plate is placed in the press and a v-shaped die is pressed a predetermined distance to bend the plate to the desired angle. Wing brakes and hand powered brakes are sometimes used.

Tube bending machines have specially shaped dies and mandrels to bend tubular sections without kinking them.

Rolling machines are used to form plate steel into a round section.

English Wheel
English Wheel
The English wheel, in Britain also known as a Wheeling machine, is a metalworking tool that enables a craftsman to form compound curves from flat sheets of metal such as aluminium or steel. The process of using an English wheel is known as Wheeling...

 or Wheeling Machines are used to form complex double curvature shapes using sheet metal.

Machining

Fab shops will generally have a limited machining capability including; metal lathe
Lathe (metal)
A metal lathe or metalworking lathe is a large class of lathes designed for precisely machining relatively hard materials. They were originally designed to machine metals; however, with the advent of plastics and other materials, and with their inherent versatility, they are used in a wide range of...

s, mill
Milling machine
A milling machine is a machine tool used to machine solid materials. Milling machines are often classed in two basic forms, horizontal and vertical, which refers to the orientation of the main spindle. Both types range in size from small, bench-mounted devices to room-sized machines...

s, magnetic based drills
Drill
A drill or drill motor is a tool fitted with a cutting tool attachment or driving tool attachment, usually a drill bit or driver bit, used for drilling holes in various materials or fastening various materials together with the use of fasteners. The attachment is gripped by a chuck at one end of...

 along with other portable metal working tools.

Welding

Welding is the main focus of steel fabrication. The formed and machined parts will be assembled and tack welded into place then re-checked for accuracy. A fixture may be used to locate parts for welding if multiple weldments have been ordered.

The welder then completes welding per the engineering drawings, if welding is detailed, or per his own judgment if no welding details are provided.

Special precautions may be needed to prevent warping of the weldment due to heat. These may include re-designing the weldment to use less weld, welding in a staggered fashion, using a stout fixture, covering the weldment in sand during cooling, and straightening operations after welding.

Straightening of warped steel weldments is done with an Oxy-acetylene torch and is somewhat of an art. Heat is selectively applied to the steel in a slow, linear sweep. The steel will have a net contraction, upon cooling, in the direction of the sweep. A highly skilled welder can remove significant warpage using this technique.

Steel weldments are occasionally annealed
Annealing (metallurgy)
Annealing, in metallurgy and materials science, is a heat treatment wherein a material is altered, causing changes in its properties such as strength and hardness. It is a process that produces conditions by heating to above the recrystallization temperature, maintaining a suitable temperature, and...

 in a low temperature oven to relieve residual stress
Residual stress
Residual stresses are stresses that remain after the original cause of the stresses has been removed. They remain along a cross section of the component, even without the external cause. Residual stresses occur for a variety of reasons, including inelastic deformations and heat treatment...

es.

Final assembly

After the weldment has cooled it is generally sand blasted, primed and painted.
Any additional manufacturing specified by the customer is then completed. The finished product is then inspected and shipped.

Specialities

Many fabrication shops have speciality processes which they develop or invest in, based on their customers needs and their expertise:
  • brazing
    Brazing
    Brazing is a metal-joining process whereby a filler metal is heated above and distributed between two or more close-fitting parts by capillary action. The filler metal is brought slightly above its melting temperature while protected by a suitable atmosphere, usually a flux...

  • casting
  • chipping
  • drawing
    Drawing (manufacturing)
    Drawing is a metalworking process which uses tensile forces to stretch metal. It is broken up into two types: sheet metal drawing and wire, bar, and tube drawing. The specific definition for sheet metal drawing is that it involves plastic deformation over a curved axis...

  • extrusion
    Extrusion
    Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed or drawn through a die of the desired cross-section...

  • forging
    Forge
    A forge is a hearth used for forging. The term "forge" can also refer to the workplace of a smith or a blacksmith, although the term smithy is then more commonly used.The basic smithy contains a forge, also known as a hearth, for heating metals...

  • heat treatment
    Heat treatment
    Heat treating is a group of industrial and metalworking processes used to alter the physical, and sometimes chemical, properties of a material. The most common application is metallurgical. Heat treatments are also used in the manufacture of many other materials, such as glass...

  • hydroforming
    Hydroforming
    Hydroforming is a cost-effective way of shaping malleable metals such as aluminum or brass into lightweight, structurally stiff and strong pieces. One of the largest applications of hydroforming is the automotive industry, which makes use of the complex shapes possible by hydroforming to produce...

  • oven soldering
    Soldering
    Soldering is a process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, the filler metal having a lower melting point than the workpiece...

  • plastic fabrication
  • powder coating
    Powder coating
    thumb|right|Aluminium extrusions being powder coatedPowder coating is a type of coating that is applied as a free-flowing, dry powder. The main difference between a conventional liquid paint and a powder coating is that the powder coating does not require a solvent to keep the binder and filler...

  • powder metallurgy
    Powder metallurgy
    Powder metallurgy is the process of blending fine powdered materials, pressing them into a desired shape , and then heating the compressed material in a controlled atmosphere to bond the material . The powder metallurgy process generally consists of four basic steps: powder manufacture, powder...

  • punching
    Punching
    Punching is a metal forming process that uses a punch press to force a tool, called a punch, through the workpiece to create a hole via shearing. The punch often passes through the work into a die. A scrap slug from the hole is deposited into the die in the process. Depending on the material being...

  • shearing
  • spinning
    Metal spinning
    Metal spinning, also known as spin forming or spinning, is a metalworking process by which a disc or tube of metal is rotated at high speed and formed into an axially symmetric part. Spinning can be performed by hand or by a CNC lathe....

  • English wheel
    English Wheel
    The English wheel, in Britain also known as a Wheeling machine, is a metalworking tool that enables a craftsman to form compound curves from flat sheets of metal such as aluminium or steel. The process of using an English wheel is known as Wheeling...

    ing
  • welding


And higher-level specializations such as:
  • electrical
  • hydraulics
    Hydraulic machinery
    Hydraulic machines are machinery and tools that use liquid fluid power to do simple work. Heavy equipment is a common example.In this type of machine, hydraulic fluid is transmitted throughout the machine to various hydraulic motors and hydraulic cylinders and which becomes pressurised according to...

  • prototyping/machine design/technical drawing
    Technical drawing
    Technical drawing, also known as drafting or draughting, is the act and discipline of composing plans that visually communicate how something functions or has to be constructed.Drafting is the language of industry....

  • sub-contract manufacturing
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