An area of inactive metal that generally remains dormant and stagnant throughout the extrusion process. These zones are inherent to the process and are normally found inside the mandrel of a hollow die and in direct extrusion inside the container adjacent to the die.

Fully annealed, the softest form of a metal, the temper of aluminum.

Removing burrs, sharp edges, or fins from metal parts by filing, grinding, or tumbling.

Forming a deeply recessed part by forcing sheet metal to undergo plastic flow between dies, usually without substantial thinning of the sheet.

A defect is anything that renders the aluminum unfit for the specific use for which it was ordered.

The distortion or bending of the die or components thereof. Insufficient support of die will cause it to deflect, lessening the effectiveness of the bearing; also termed dishing, caving, and sagging.

Weight per unit of volume (for example pounds per cubic foot). The density of aluminum is only about one-third that of steel, and this weight-saving characteristic is one of aluminum's best-known advantages.

A sharply defined surface impression on the metal which may be caused by a blow from another object.

Localized surface deviation from flat generated by expansion of vapor during thermal treatment of cold rolled coiled sheet.

Repeating depression caused by a particle adhering to a rotating roll over which the metal has passed.

The depth to which base metal melts during welding.

A past-oriented strategy that attempts to identify unacceptable output after is has been produced and then separate it from the good output.

The temperature of a circular object, measured from the center to the edge (average).

In extrusion a tool with an opening through which heated aluminum is forced by pressure, taking on that cross-sectional shape.

In an extrusion press, the die and its associated tooling.

The surface of an extrusion die facing the billet.

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The press component which is located between the container and press platen to retain the extrusion die and its components. It may take many different forms and added functions depending upon its design. The holder can be unlocked and the die withdrawn for the removal of butt and scrap.

A steel extrusion tool which forms extruded closed profiles containing one or more voids such as rectangular tubing. The tool generally consists of a die cap which generates the outer surface of the profile and the mandrel or core which generates the inside contour. Hollow or semi-hollow profiles are produced usually with either bridge, porthole or spider (taper seal) type dies or variants thereof. Extruded sections produced on such dies have seams or longitudinal weld lines, due to the metal flow around the web supports (bridges) that hold the mandrel. The latter determines the inside contour of the profile being extruded. After flowing around the supports, the metal is fused in a weld chamber before passing through the die (die cap) proper.

The sectional irregularities caused by an uneven extrusion rate, or by material either not being led from the die in a uniform manner or being adequately supported.

A longitudinal depression or protrusion formed on the surface of drawn or extruded material. Die lines are present to some degree in all extrusions and are caused by a roughening of the die bearing.

The number assigned to a die for identification and cataloging purposes, and which usually is assigned for the same purpose to the product produced from that die.

A cylindrical sleeve that holds the die and backer in axial relationship to each other.

A circular steel extrusion tool which forms an open profile with a high tongue ratio. Generally this tongue ratio is greater than three to one. This type of die is similar to a hollow die. The tongue is protected by a web or bridge which reduces the billet pressure. When possible, for maximum support the tongue should be bolted to the web.

The extrusion press component located between the container and press platen. It supports, aligns to the press and retains the tooling (die, backer, bolster, sub-bolster, etc.) for the specified profile, as a unit. It may be designed to facilitate butt shearing and to provide die accessibility for replacement and repairing.

A steel disk, with one or more orifices or apertures, of similar cross-section and contour as the desired product, through which metal is forced forming open profiles such as bar, channel and angle.

A defect resembling a weld around the entire extruded section, caused by stopping a press during extrusion and then restarting it.

The various components making up the assembly within the tool carrier or Die Slide. A typical example would be (from front to rear): die and backer enclosed in a die ring, bolster and possibly a sub-bolster or spacer.

A region in extruded hollow profiles created by two streams of metal within the die joining themselves in the weld chamber around the mandrel of a hollow type die. Die welds are generally present in all extruded hollow profiles and in most cases are not visible.

The specified difference in size between mating parts.

The ability of an object to retain its original shape under varying physical conditions.

Coating of parts by dipping them into a tank of continuously agitated paint and withdrawing them slowly to prevent tearing of the paint film or retention of drops on the edges.

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Foreign debris.

(1) A circular blank fabricated from plate, sheet, or foil, from which a central concentric area has been removed. (2) An electrostatic paint application shaped like a disc which atomizes paint utilizing centrifugal force off the edge of the disc.

Abnormalities such as cracks, laps, folds, cold shuts, inclusions, segregation and porosity. Voids of any kind.

Any deviation from the desired shape or contour.

An interlocking connection frequently used for the assembly of interconnecting extrusions; it is assembled by a sliding action.

Taper on the sides of a die or mold impression to facilitate removal of forgings, castings or patterns from dies or molds.

A hot worked intermediate solid or tubular product of uniform cross section along its whole length, supplied in coils and of a quality suitable for drawing into tube or wire.

A product formed by pulling material through a die.

A foil surface substantially free from oily film, and suitable for lacquering, printing, or coating with water-dispersed adhesives.

The property that permits permanent deformation before fracture by stress in tension.

Coiled or flat sheet in specific tempers, widths and thicknesses, suitable for duct applications.

A tight-fitting steel block placed between the ram and the billet in an extrusion press to prevent metal from leaking backward along the ram during extrusion.

Electrical conductor aluminum, an alloy specifically formulated for good electrical conductivity; it is about 99.5 percent aluminum. Typically AA1350 alloy.

A process that utilizes high frequency pulsating DC current in the presence of a dielectric to erode tool steel. The Ram or Plunge EDM process is utilized for burning relief into the back of the die, or burning the shape into the mandrel core. Wire EDM is utilized to cut die openings in dies.

Wavy symmetrical projections formed during cupping, deep drawing or spinning. Earing is caused by non-uniform directional properties in the aluminum and/or by improperly adjusted tooling.

Wavy symmetrical projections formed in the course of deep drawing or spinning as a result of directional properties or anisotropy in sheet. Ears occur in groups of 4 or 8 with the peaks of the projections located at 45 degrees and/or at 0 and 90 degrees to the rolling direction. Degree of earing is the difference between average height at the peaks and average height at the valleys, divided by average height at the valleys, multiplied by 100 and expressed in percent.

Deviation from a common center, as, for example, the inner and outer walls of a round tube. The difference between the mean wall thickness and minimum or maximum wall thickness at any one cross section. The permissible degree of eccentricity can be expressed by a plus and minus wall-thickness tolerance.

Excessive buildup of material on edge(s) during a rewinding operation. Typical causes include excessive edge burr, turned edge, and dog bone shaped cross sectional profiles.

Edge(s) containing crack, split, and/or tear which may be caused by an inability to deform without fracturing.

Edge of a coil that has been bent, torn, or scraped by an object.

A continuous, downward edge deflection.

Surface condition remaining after portions of a side of an as-cast rolling ingot deforms enough during hot rolling to become top and/or bottom surface(s) of the rolled product at an edge.

A temporary dimensional change induced by stress. The body returns to its original dimensions when the stress is removed if its elastic limit has not been surpassed.

The ability of a material or body to return to its original shape and dimensions after being deformed by stress.

The maximum stress that a body can withstand without permanent deformation.

The capacity of a material to conduct electric current. For

aluminum, this capacity is expressed as a percentage of the International Annealed Copper Standard (IACS), which has a resistivity of 1/58 ohm-mm2/meter at 68ºF and an arbitrarily designated conductivity of unity.

The electrical resistance of a body of unit length and unit cross-sectional area or unit weight. The value of 1/58 ohm-mm2/meter at 68ºF is the resistivity equivalent to the International Annealed Copper Standard for 100 percent conductivity. This means that a wire of 100 percent conductivity, 1 meter in length and 1 square millimeter in cross-sectional area would have a resistance of 0.017241 ohms at 68 degrees F.

Pertaining to chemical reactions induced by an electric current such as electrolysis or electroplating.

Application of a coating by immersing the parts in a bath of water containing resin, electrolytic stabilizers and pigments, an electric current is passed through the bath, using the parts as anodes, plating them with resins and color.

The separation of a chemical compound into its components by passing an electric current through it.

A dissolved or fused substance capable of conducting an electric current, examples include the molten solution electrolyzed in an aluminum reduction cell, or the acid solution in a wet-cell battery.

Depositing a thin layer of a metal, usually copper, tin or silver, on the surface of another metal by electrifying the metal to be plated in an electrolyte containing the plating metal.

A system of applying paint in which the paint droplets or powder particles are given an electrical surface charge resulting in their attraction to a grounded workpiece. Higher transfer efficiency, better wrap and penetration, finer atomization and less overspray are distinct advantages.

Application of a coating by applying a static electricity charge to the droplets of a spray and an opposite charge to the part being sprayed, which then attracts the droplets directly to its surface.

The percentage increase in distance between two gauge marks that results from stressing the specimen in tension to fracture. The original gauge length is usually 2 inches for flat specimens and round specimens whose diameter is 0.5 inch, or four times the diameter for specimens where that dimension is under 0.5 inch. Elongation values depend to some extent upon size and form of the test specimen. For example, the values obtained from sheet specimens will be lower for thin sheet than for thicker sheet.

Raising a design in relief against a surface.

Reduction in the normal ductility of a metal, due to physical or chemical change.

The relative ability of a material to radiate energy per unit of surface area expressed as a ratio to the radiation rate of an ideal black body of identical area and temperature.

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The limiting stress below which a material will withstand a specified large number of cycles of stress.

The diameter of a circle having a circumference equal to the outside perimeter of other than round tube.

Chemical solutions used to change the metal surface for cleaning, examination or for finishing.

Shaping or texturing a metal surface by controlled corrosive action.

Any face of an extruded profile which is exposed to view or other critical end-use aspects.

The general process of separating a metal from its ore.

To force material through a die by pressure.

The length of a profile (section) extruded in a single push.

A profile usually of constant cross section brought to final dimensions by extruding. The preferred term describing an extrusion formerly termed an extruded shape.

Any aluminum extrusion other than rod, bar, or tube.

The starting stock for the extrusion operation. Extrusion billet is a solid or hollow form, commonly cylindrical and is the length charged into the extrusion press cylinder. It is usually a cast product but may be a wrought product or powder compact.

A longitudinal discontinuity in the extreme rear portion of an extruded product, which is normally discarded.

A cone-shaped abnormality such as a cavity in an extruded product (ring in a hollow profile or tube) formed in the extreme rear portion, if extruded too far.

The method of extruding wherein the die and ram are at opposite ends of the billet and the product and ram travel in the same direction.

The method of extruding where the die is at the ram end of the billet and the product travels through the hollow ram and in the opposite direction.

A cast form that is solid or hollow, usually cylindrical, suitable for extruding. See also Fabricating Ingot.

A cast solid extrusion ingot which has been drilled to make it hollow.

A cast solid or hollow extrusion ingot which has been machined on the outside surface. Scalped billets are normally used with the indirect extrusion process.

The starting stock for extrusion billet. Extrusion log is usually produced in lengths from which shorter extrusion billets are cut.

That force employed to cause billet metal flow through a die.

A region in extruded hollow profiles observed after creating two streams of metal and rejoining them around the mandrel of a porthole or bridge die.

The velocity or rate at which an extrusion exits from the die usually expressed as feet per minute.

The auxiliary equipment required to produce extrusions, which is not an integral or fixed part of the extrusion press. Tools consist principally of container, dies, die backers, dummy blocks, etc.