ALUMINUM GLOSSARY - G

Galvanic Corrosion

Deterioration of a metal caused by the electric current produced when two unlike metals are in contact under certain condition.

Galvanizing

An undesirable grainy or spangled condition on the surface of etched or anodized extrusions. This condition is not obvious in mill finish aluminum extrusions but can be revealed by etching or anodizing.

Gas Entrapment

A situation that occurs when air is trapped inside the die or container, usually during the dead cycle, as a result of sloppy butt shearing or the upsetting of the billet inside the container.

Gasket

A relatively soft sealer often of cork, asbestos, or rubber placed in a joint between two metal parts to prevent leakage through the joint.

Gauge

A term previously used in referring to the thickness or diameter of a wrought product. Thickness or diameter is preferred in dimensional descriptions.

German Mandrel

Fixed mandrel.

Gloss

The degree to which a surface reflects light, generally, the smoother the surface, the higher the gloss.

Grain Flow

The directional characteristics of the metal structure after working, revealed by etching a polished section.

Grain Size

A measure of crystal size usually reported in terms of average diameter in millimeters, grains per square millimeter, or grains per cubic millimeter.

Grinding

Removing material from a workpiece with an abrasive wheel.