ALUMINUM GLOSSARY - F

Fabricate

To work a material into a finished state by machining, forming or joining.

Fabricating Ingot

A cast form suitable for subsequent working by such methods as rolling, forging, extruding, etc.

Fat Edge

An application defect where too much paint accumulates along a square edge or corner of the part, often evidenced by higher gloss or blistering.

Fatigue

The tendency for a metal to break under conditions of repeated cyclic stressing considerably below the ultimate tensile strength.

Fatigue Strength

The maximum stress that a metal can sustain for a specified number of cycles without failure.

Faying Surface

The surface of a piece of metal in contact with another to which it is, or will be, joined.

Feed

Pertains to the amount of aluminum directed to a specific area of an extrusion die, generally achieved by adjusting the port size.

Feeder Die

A die design which permits through certain design features the extrusion of profiles normally too large for an extrusion press if conventional means were employed or to assist in extrusion of difficult profiles.

Feeder Plate

A plate employed in front of the extrusion die to alter the metal billet dimensions permitting extrusion of larger dimensioned product than normally possible or to assist in extrusion of difficult profiles.

Ferrous

Pertaining, derived from, or based on iron.

Filler Metal

Metal added in making a brazed, soldered or welded joint.

Fillet

Generally, a concave junction where two surfaces meet.

Fillet Weld

A weld, approximately triangular in cross section, joining two surfaces at right angles to each other.

Film Thickness

The depth of applied coating, expressed in mils, i.e. 1/1000 inch.

Fin

A thin projection on a forging or casting resulting from trimming or from the metal under pressure being forced into hairline cracks in the die or around die inserts.

Fin Stock

Coiled sheet or foil in specific alloys, tempers, and thickness ranges suitable for manufacture of fins for heat-exchanger applications.

Finish

In extrusion, the condition, quality or appearance of the final aluminum surface. Aluminum can be finished in a very wide variety of textures and colors.

Finishing

Usually secondary operations applied to extrusions to improve product dimensionally or change surface condition (etching) or color (anodizing, plating, painting, buffing, etc).

Fisheye

A defect in the paint film appearing as a circular depression resembling a crater but not revealing bare substrate.

Fishtail Die Extruding

The utilization of a transition piece of tooling between the container and die (feeder plate), whereby a conventional round billet is forced to assume the elliptical shape of the cavity and opening in the transition piece, before reaching the aperture of the die proper, thus allowing sections to be extruded that are much wider than the container. Such dies can also be made in one piece (feeder die), incorporating the same principles.

Fit

The range of clearance or interference between mating parts. The American Standards Association recognizes 33 classes of fits ranging from loose sliding fit to tight force fit.

Fixed Dummy Block

A dummy block attached to the ram with self expansion capabilities.

Flag

A marker inserted adjacent to the edge at a splice or lap in a coiled product.

Flaking

A condition in coated sheet where portions of the coating become loosened due to inadequate adhesion.

Flash

A thin protrusion at the parting line of a forging or casting which forms when metal, in excess of that required to fill the impressions, is forced between the die interfaces. Also, metal forced between container and die due to improper seal.

Flash Line

A line left on a forging or casting where flash has been removed.

Flat Layout

The design method of locating the apertures in a die so that the major axis of each profile is parallel to each other and may be mirrored.

Flatness

(1) For rolled products, a distortion of the surface of sheet such as a bulge or a wave, usually transverse to the direction of rolling. Often described by location across width, i.e., edge buckle, quarter buckle, center buckle, etc. (2) For extrusions, flatness (off contour) pertains to the deviation of a cross-section surface intended to be flat. Flatness can be affected by conditions such as die performance, thermal effects and stretching.

Flexibility

(1) The capability of a material to be curved, folded, or bent. (2) The ability of a paint to resist chipping, peeling, or cracking after the substrate has been bent, twisted, bowed, or punched.

Floating (Fixed) Dummy Block

A fixed dummy block design which has self alignment capabilities.

Flow

A term used when referring to the movement of aluminum through the die during the extrusion process.

Flow Line

(1) Lines on the surface of painted sheet, brought about by incomplete leveling of the paint. (2) The line pattern revealed by etching, which shows the direction of plastic flow on the surface or within a wrought structure.

Flow Through

A forging defect caused when metal flows past the base of a rib resulting in rupture of the grain structure.

Flow Coating

Painting a part by directing streams of paint against it and letting excess paint drain into a tank for recirculation. Complicated shapes can be painted this way, but they must be correctly positioned for paint drainage.

Fluorocarbon

A stable carbon compound in which hydrogen from a hydrocarbon has been replaced by fluorine. Coatings containing the fluorocarbon PVF2, among the most stable known, are applied by roll coating or spray.

Fluxing

The removal of impurities from molten metal in a crucible, furnace, or scrap remelting furnace by bubbling a mixture of gasses up through the melt. The combined chemical and mechanical action carries oxides and other impurities to the top of the melt, forming a scum or dross that is skimmed off.

Formability

The relative ease with which a material can be shaped through plastic deformation.

Forming

Changing the shape of metal except by shearing or blanking without intentionally altering its thickness.

Fracture

A generic term for measure of resistance to extension of a crack.

Frictional Heat

That heat imparted to the extrusion or billet as the result of metal movement within the container or through the die.