A tool, or reinforcing part, which presses against the outer surface of an extrusion die, supporting it against the pressure of the extruding metal. The backer has an opening larger than the die aperture, allowing the extruded product to emerge without marring its soft surface.

Nongrooved rolls which stiffen or strengthen work rolls.

Cut-away portion of die beginning at breakaway point to the die

exit either angled or undercut (stepped back) for back clearance.

The curing of paint at an elevated temperature for a specific period of time, allowing the paint to become hard and dry.

A solid extrusion that is long in relation to cross section, which is square or rectangular (excluding plate or flattened wire) with sharp or rounded corners or edges; or is a regular hexagon or octagon; and in which at least one perpendicular distance between parallel faces is 0.375 inch or greater. (Smaller sizes are classified as wire.)

Bar brought to final dimensions by cold work to obtain improved surface finish and dimensional tolerances.

Cold-finished bar produced from extruded bar.

Cold-finished bar produced from rolled bar.

Bar brought to final dimensions by hot extruding

Bar brought to final dimensions by hot rolling.

(1) The metal present in the largest proportion in an alloy; (2) the metal to be brazed, cut or welded; (3) after welding, the part of the metal that was not melted during the process.

One of the ores from which alumina is extracted and from which aluminum is eventually smelted. Bauxite usually contains at least 45 percent aluminum oxide (alumina), and the best grades have a low silica content. About four pounds of bauxite is required to produce one pound of aluminum.

The principal horizontal load-bearing member of a structure.

The surface of the extruding aperture, at right angles to the die face, that controls metal flow and to some extent speed of flow which is also the conforming surface along which the aluminum flows.

Electrostatic spray device whose paint applicator is bell-shaped, atomizing paint off its edge.

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The area of a liner that has an increased inside diameter from nominal, appearing convex (may be caused by a weak container).

May be solid or hollow in form, commonly cylindrical, used as the final length of material charged into the extrusion press cylinder. It is usually a cast product, but may be a wrought product or sintered from powder compact.

The part of an extrusion press into which the billet to be extruded is placed.

An aluminum alloy containing a relatively large amount of only one other element.

A piece of metal cut or formed to regular or irregular shape for subsequent processing such as by forming, bending, or drawing. The piece of sheet stock cut out by blanking die. It will subsequently be drawn into a cup or end shell.

The machining of the transition in the bearing length from long to short.

A raised area on the surface of an extruded product due to subsurface gas expansion during extrusion or thermal treatment.

A raised area on only one surface of the metal whose origin is between the cladding and core in clad products.

A blister in the coating of an alclad or a clad product.

A raised area (one or both sides) on rolled metal.

A defect in the paint film appearing as bubbles, usually caused by the expansion of air, solvent vapor, or moisture trapped beneath the film.

The use of graphite blocks to support the emerging extrusion as it exits the die.

A semi-finished hot rolled product, rectangular or square in cross section, produced on a blooming mill.

A blister that has ruptured and may produce a void. See also Blister.

A tool, or reinforcing part, which supports the backer -- which, in turn, supports an extruding die against the pressure of extrusion.

Longitudinal curvature of rod, bar, profiles (shapes), and tube. Bow is measured after allowing the weight of the extrusion to minimize the deviation. Bow can be caused by a non-uniform extrusion rate across the cross section resulting in one portion of the extrusion being longer than the other or non-uniform contraction during quenching.

Deviation from straight of a longitudinal edge.

Curvature in the case of sheet or plate in the rolling direction, along the length of an extrusion.

Curvature across the rolling direction of sheet or plate, across the width of an extrusion.

Joining metals by fusion of nonferrous alloys that have melting points above 425ºC (800ºF) but lower than those of the metals being joined. This may be accomplished by means of a torch (torch brazing), in a furnace (furnace brazing), or by dipping in a molten flux bath (dip or flux brazing).

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A rolled, extruded, or cast round filler metal for use in joining by brazing.

Sheet of a brazing alloy, or sheet clad with a brazing alloy on one or both sides.

Wire for use as a filler metal in joining by brazing.

Is usually formed by the step where die undercut starts and bearing surface ends and is also where the extrusion leaves the bearing.

The initial pressure required to start metal flow through the extrusion die.

The point in time when the billet emerges from the exit side of the die as an extruded profile.

In extrusion: the part of an extrusion bridge die that supports a void-forming mandrel. During extrusion, the metal divides and flows around the bridge, reuniting as it is extruded through the die orifice. The resulting weld line can be detected upon microscopic examination, but the extrusion appears functionally and visually seamless.

A die having a stationary core or mandrel which is held in place by core supports or webs (bridge) bolted to the back of the die. The die contains a weld chamber so that when the billet is pushed the metal divides to flow around the core supports and welds together in the welding chamber before passing through the die. See Porthole Die and Spider Die. Bridge dies normally have unenclosed ports which protrude into the container liner.

The network of support webs which hold in place the internal surface forming portion of the mandrel, created when the ports are machined into the mandrel.

Is used to reduce pressure on critical tongue areas of a semi-hollow or hollow die.

Chemical polishing of aluminum, often by treatment with a mixture of nitric acid and phosphoric acid, yielding a mirror-shiny (specular), highly reflective surface. It is almost always followed by anodizing to protect the surface and provide some choice of colors.

See Sheet, (1SBMF), (S1SBF) and (S2SBF).

See Hardness, Brinnell.

A deviation from the desired cross section due to the absence of a certain portion of the die used to extrude the profile (shape).

Nonuniform surface on the inside of packed rolled foil (Bright Finish Spots).

A distortion of the surface of the metal.

Bend, crease, wrinkle, or departure from flat, occurring perpendicular to the slit edge of a coil and which are repetitive in nature, with severity decreasing as the distance increases in the coil from the original source. Normally, it is found on the ID of a coil but can appear on the coil OD as a result of a prior winding operation.

Undulation (wavy region) in the center of the metal.

Undulation (wavy region) along the edge(s) of the metal.

Undulation (wavy region) which occur approximately at both quarter points across the width.

Undulation (wavy region) which is smaller sized and often circular in shape.

A mechanical finishing operation in which fine abrasives are applied to a metal surface by rotating fabric wheels for the purpose of developing a lustrous finish.

A thin ridge of roughness left by a cutting operation such as slitting, trimming, shearing, blanking, or sawing.

Tiny, almost microscopic shards of die steel protruding into the die aperture (opening), usually from either the entry or exit edge of the bearing. They are typically formed during the manufacture of the die but can also be formed by striking the die opening with a hammer, dies bumping together during handling or other abnormal impacts to the die face.

The pressure required to rupture a foil specimen when it is tested in a Mullen instrument under specified conditions. See also Mullen Test.

A rigid electric conductor in the form of a bar.

The unextruded portion of the billet remaining in the container after the extrusion cycle is completed. The butt varies in thickness depending upon the alloy, die configuration, and extruded profile characteristics.

The residual portion of an extrusion billet that is not formed through the die at the end of the extrusion cycle.

The welding of two sections that butt against each other, end to end.