ALUMINUM GLOSSARY - T

Taper Heating

A staged or gradient heating.

Taper Seal Die

A type of hollow die using a taper or conical angle to seal the die and its ring.

Tear, Speed

A series of surface cracks perpendicular to the extruding direction. Speed tearing normally occurs in corner radii or extremities of a section and is caused by localized high temperature.

Tearing

Typically cracks or separations due to high extrusion speed or extrusion temperature.

Telescoping

Lateral stacking, primarily in one direction, of wraps in a coil so that the edges of the coil are conical rather than flat. Improper alignment of rolls over which the metal passes before rewinding is a typical cause. See also Oscillation.

Temper

The combination of hardness and strength imparted to a metal by mechanical or thermal treatments and characterized by certain metallurgical structures and mechanical properties determining temper designation.

Tensile Strength

In tensile testing, the ratio of maximum load to original cross-sectional area. Also called Ultimate Strength.

Thermal Conductivity

The ability of a material to transmit heat through its bulk and, by direct contact, to other substances. Aluminum is a good heat conductor and is widely used in cookware and in radiators and other heat exchangers.

Tolerance

Allowable deviation from a nominal or specified dimension.

Tongue

That portion of die cap metal surrounded by the aperture except at one end which is termed the base of the tongue.

Tongue (of an extrusion die)

An area of a die surrounded on three sides by the extrusion aperture.

Tongue Cave

Distortion of the die tongue.

Tongue and Groove Joint

A joint in which one part has a groove which receives a projection (tongue) on the other part, shaped to fit snugly.

Tonnage

Press hydraulic pressure times cylinder area, expressed in U.S. tons.

Tool

A term usually referring to the dies, mandrels, etc., used in the production of extruded or drawn profiles or tube.

Tools or Tooling

The parts of an extrusion press that are changed to produce a specific shape. Tools include dies and mandrels, and various supporting parts.

Tool Deflection

See Deflection . The distortion, displacement or caving in the extrusion direction of the extrusion die or tool surface under extrusion pressure.

Tool Rub

A surface area showing a scratch or abrasion resulting from contact of the hot extrusion with the press equipment or tooling or, in the case of multi-hole dies, with other sections as they exit the press.

Tooling Plate

A cast or rolled product of rectangular cross section of thickness 0.250 inch or greater, and with edges either as-cast, sheared or sawed, with internal stress levels controlled to achieve maximum stability for machining purposes in tool and jig applications.

Topcoat

In a multi-coat system, the coat applied over a primer, usually the final coat applied.

Torn Surface

A deep longitudinal rub mark resulting from abrasion by extrusion or drawing tools.

Toxicity

The degree to which a substance is toxic, or poisonousness.

Traffic Mark

Abrasion which results from relative movement between contacting metal surfaces during handling and transit. A dark color from the abrasively produced aluminum oxide is usually observed. A mirror image of a traffic mark is observed on the adjacent contacting surface.

Transverse Direction

A direction perpendicular to the direction of working.

Transverse Weld

A condition existing within an extrusion which is created by the interface of two separate billets. In practice the interface is extruded at different rates through the die and is formed into a conical or pointed configuration within a portion of the extrusion.

Tread Plate

Sheet or plate having a raised figured pattern on one surface to provide improved traction.

Trend

A gradual, systematic change with time or other variables.

Trim Inclusion

Edge trimming accidentally wound into a roll of foil.

Tube

A hollow wrought product that is long in relation to its cross section, which is symmetrical and is round, a regular hexagon or octagon, elliptical, or square or rectangular with sharp or rounded corners, and that has uniform wall thickness except as affected by corner radii.

Tube Bloom

This term is not recommended. The term Tube Stock is preferred.

Tube Stock

A semi-finished tube suitable for the production of drawn tube.

Tube, Butt-Welded

A welded tube, the seam of which is formed by positioning one edge of the sheet against the other for welding.

Tube, Drawn

A tube brought to final dimensions by drawing through a die.

Tube, Embossed

A tube the outside surface of which has been roll-embossed with a design in relief regularly repeated in a longitudinal direction.

Tube, Extruded

A tube formed by hot extruding.

Tube, Finned

Tube which has integral fins or projects protruding from its outside surface.

Tube, Fluted

A tube of nominally uniform wall thickness having regular, longitudinal, concave corrugations with sharp cusps between corrugations.

Tube, Heat-Exchanger

A tube for use in apparatus in which fluid inside the tube will be heated or cooled by fluid outside the tube. The term usually is not applied to coiled tube or to tubes for use in refrigerators or radiators.

Tube, Helical-Welded

A welded tube produced by winding the sheet to form a closed helix and joining the edges of the seam by welding.

Tube, Lap-Welded

A welded tube the seam of which is formed by longitudinally lapping the edges of the sheet for welding.

Tube, Redraw

This term is not recommended. The term Tube Stock is preferred.

Tube, Seamless

Tube that does not contain any line junctures (metallurgical welds) resulting from the method of manufacture. This product may be produced by die-and-mandrel or by hot-piercer processes. Tube produced by porthole-die extrusion, bridge-die extrusion, or welding processes is generally not considered Seamless. (Seamless tube is typically used for fluid-carrying applications under pressure.)

Tube, Sized

A tube that, after extrusion, has been cold drawn a slight amount to minimize ovality.

Tube, Stepped Drawn

A drawn tube whose cross section changes abruptly in area at intervals along its length.

Tube, Structural

Tube commonly used for structural purposes.

Tube, Welded

A tube produced by forming and seam-welding sheet longitudinally.

Tubing, Electrical Metallic

A tube having certain standardized length and combinations of outside diameter and wall thickness thinner than that of Rigid Conduit , commonly designated by nominal electrical trade sizes, for use with compression-type fittings as a protection for electric wiring.

Tubing Product

A general term comprising tube, hollow profiles, and semi-hollow profiles.

Tubular Conductor

A tubular product suitable for use as an electric conductor.

Twist

(1) For rolled products, a winding departure from flatness. (2) For extrusions, a winding departure from straightness.

Two-Tone

A sharp color demarcation in the appearance of the metal due to a difference in the work roll coating.