sheet metal fabrication Manufacturers

sheet metal fabrication 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. Thicknesses can vary significantly, although extremely thin thicknesses are considered foil or leaf, and pieces thicker than 6 mm (0.25 in) are considered plate.

sheet metal fabrication is available as flat pieces or as a coiled strip. The coils are formed by running a continuous sheet of metal through a roll slitter.

The thickness of the sheet metal fabrication is called its gauge. The gauge of sheet metal fabrication ranges from 30 gauge to about 8 gauge. The larger the gauge number, the thinner the metal.

There are many different metals that can be made into sheet metal fabrication, such as aluminum, brass, copper, steel, tin, nickel and titanium. For decorative uses, important sheet metal fabrications include silver, gold, and platinum (platinum sheet metal fabrication is also utilized as a catalyst.)

sheet metal fabrication has applications in car bodies, airplane wings, medical tables, roofs for buildings and many other things. sheet metal fabrication of iron and other materials with high magnetic permeability, also known as laminated steel cores, has applications in transformers and electric machines. Historically, an important use of sheet metal fabrication was in plate armor worn by cavalry, and sheet metal fabrication continues to have many decorative uses, including in horse tack.

Cutting sheet metal fabrication can be done in various ways from hand tools called tin snips up to very large powered shears. With the advances in technology, sheet metal fabrication cutting has turned to computers for precise cutting.

Many sheet metal fabrication cutting operations are based on computer numerically controlled (CNC) lasers cutting or multi-tool CNC punch press.

CNC laser involves moving a lens assembly carrying a beam of laser light over the surface of the metal. Oxygen, nitrogen or air is fed through the same nozzle from which the laser beam exits. The metal is heated and burnt by the laser beam, cutting the metal sheet. The quality of the edge can be mirror smooth and a precision of around 0.1 mm (0.0039 in) can be obtained. Cutting speeds on thin (1.2mm) sheet can be as high as 25m a minute. Most of the laser cutting systems use a CO2 based laser source with a wavelength of around 10 um; some more recent systems use a YAG based laser with a wavelength of around 1 um.

 PerforatingMain article: Perforating
Perforating is a cutting process that punches multiple small holes close together in a flat workpiece. Perforated sheet metal fabrication is used to make a wide variety of surface cutting tools, such as the surform.

 Press brake forming
Forming metal on a pressbrakeThis is a form of bending, used for long and thin sheet metal fabrication parts. The machine that bends the metal is called a press brake. The lower part of the press contains a V shaped groove. This is called the die. The upper part of the press contains a punch that will press the sheet metal fabrication down into the v shaped die, causing it to bend. There are several techniques used here, but the most common modern method is "air bending". Here, the die has a sharper angle than the required bend (typically 85 degrees for a 90 degree bend) and the upper tool is precisely controlled in its stroke to push the metal down the required amount to bend it through 90 degrees. Typically, a general purpose machine has a bending force available of around 25 tonnes per metre of length. The opening width of the lower die is typically 8 to 10 times the thickness of the metal to be bent (for example, 5mm material could be bent in a 40mm die) the inner radius of the bend formed in the metal is determined not by the radius of the upper tool, but by the lower die width. Typically, the inner radius is equal to 1/6 of the V width used in the forming process.

The press usually has some sort of back gauge to position depth of the bend along the workpiece. The backgauge can be computer controlled to allow the operator to make a series of bends in a component to a high degree of accuracy. Simple machines control only the backstop, more advanced machines control the position and angle of the stop, its height and the position of the two reference pegs used to locate the material. The machine can also record the exact position and pressure required for each bending operation to allow the operator to achieve a perfect 90 degree bend across a variety of operations on the part.

 PunchingMain article: Punching
Punching is performed by placing the sheet of metal stock between a punch and a die mounted in a press. The punch and die are made of hardened steel and are the same shape. The punch just barely fits into the die. The press pushes the punch against and into the die with enough force to cut a hole in the stock. In some cases the punch and die "nest" together to create a depression in the stock. In progressive stamping a coil of stock is feed into a long die/punch set with many stages. Multiple simple shaped holes may be produced in one stage but complex holes are created in multiple stages. The final stage the part is punched free from the "web".

A typical CNC punch has a choice of up to 60 tools in a "turret" that can be rotated to bring any tool to the punching position. A simple shape (e.g. a square, circle, or hexagon) is cut directly from the sheet. A complex shape can be cut out by making many square or rounded cuts around the perimeter. A punch is less flexible than a laser for cutting compound shapes, but faster for repetitive shapes (for example, the grille of an air-conditioning unit). A CNC punch can take 600 strokes per minute.

A typical component (such as the side of a computer case) can be cut to high precision from a blank sheet in under 15 seconds by either a press or a laser CNC machine.

 Roll formingMain article: Roll forming
A continuous bending operation for producing open profiles or welded tubes with long lengths or in large quantities.

 Rolling
Bending sheet metal fabrication with rollersMain article: Rolling
 SpinningMain article: Metal spinning
Spinning is used to make tubular(axis-symmetric) parts by fixing a piece of sheet stock to a rotating form (mandrel). Rollers or rigid tools press the stock against the form, stretching it, until the stock takes the shape of the form. Spinning is used to make rocket motor casings, missile nose cones, satellite dishes and metal kitchen funnels.

 StampingMain article: Stamping
Includes a variety of operations, such as punching, blanking, embossing, bending, flanging, and coining; simple or complex shapes formed at high production rates; tooling and equipment costs can be high, but labor costs are low.

Alternatively, the related techniques repouss¨¦ and chasing have low tooling and equipment costs, but high labor costs.

 Water jet cuttingMain article: Water jet cutting
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.