A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- G -
(Metal) - Mfrs. standard numbering systems indicating decimal
thickness or diameters.
The damaging of one or both metallic surfaces by removal of
particles from localized areas due to seizure curing sliding
Coating steel with zinc and tin (principally zinc) for rustproofing
purposes. Formerly for the purpose of galvanizing, cut length
steel sheets were passed singly through a bath of the molten
metal. Todays galvanizing processing method consists of
uncoiling and passing the continuous length of successive coils
either through a molten bath of the metal termed Hot Dipped Galvanizing
or by continuously zinc coating the uncoiled sheet electrolytically
- termed Electro-Galvanizing.
The form of iron stable between 1670°F., and characterized
by a face-centered cubic crystal structure.
A copper-zinc alloy containing 95% copper and 5% zinc. While
similar to deoxidized copper in physical properties, it is somewhat
stronger and very ductile. It has thermal and electrical conductivity
slightly better than half that of electrolytic copper and corrosion
resistance comparable to copper.
A solid polyhedral (or many sided crystal) consisting of groups
of atoms bound together in a regular geometric pattern. In mill
practice grains are usually studied only as they appear in one
plane. (1) Direction of: Refers to grain fiber following the
direction of rolling and parallel to edges of strip or sheets.
(2) To bend across the grain is to bend at right angles to the
direction of rolling. (3) To bend with the grain is to bend parallel
to the direction of rolling. In steel, the ductility in the direction
of rolling is almost twice that at right angles to the direction
Bounding surface between crystals. When alloys yield new phases
(as in cooling), grain boundaries are the preferred location
for the appearance of the new phase. Certain deteriorations,
such as season cracking and caustic embrittlement, occur almost
exclusively at grain boundaries.
An increase in metallic crystal size as annealing temperature
is raised; growth occurs by invasion of crystal areas by other
Individual crystals in metals.
Average diameter of grains in the metal under consideration,
or alternatively, the number of grains per unit area. Since increase
in grain size is paralleled by lower ductility and impact resistance,
the question of general grain size is of great significance.
The addition of certain metals affects grain size, for example
vanadium and aluminum tend to give steel a fine grain. The ASTM
has set up a grain size standard for steels, and the McQuaid-Ehn
Test has been developed as a method of measurement.
A coarse grain or pebbly surface condition which becomes evident
during drawing. (See Orange Peel)
The formation of grains immediately upon solidification.
A heating and cooling process by which the combined carbon
in cast iron or steel is transformed, wholly or partly, to graphitic
or free carbon.
GROUND FLAT STOCK
Annealed and preground (to close tolerances) tool steel flats
in standard sizes ready for tool room use. These are three common
grades; water hardening, oil hardening and air hardening quality.
Device for holding the metal in the proper position, during
rolling, or slitting.
(Defect) - Scratches or marks appearing parallel to edges of
cold rolled strip caused by scale or other articles which have
become imbedded in or have adhered to the rolling mill guide.
Also applies to similar scratches appearing as a result of slitting.