Guardian Metal Sales, Inc. History

Exceptional Resistance to Corrosion:
One of the most outstanding and certainly the most complex features of copper metals is their corrosive resistance. Corrosion is usually defined as a deterioration or failure of metal by chemical or electrochemical processes. However, since corrosion is a reaction of a metal's surface to its environment, deterioration does not take place until the corrosion penetrates the surface.

Many copper alloys react quickly to their environment and form a film of surface oxidation. However, this tarnish (sometimes called patina on copper) affects only the appearance and not the matrix of the metal itself. Therefore, the metal itself does not deteriorate. It is protected by the surface oxidation, which is generally not soluble in water, and which adheres tightly to the surface, preventing exposure to further environmental corrosion. Because of the protection provided by the oxidized surfaces, copper alloys enjoy an extremely long life free from bulk corrosion.

High Electrical Conductivity:
Copper has several characteristics that make it valuable in the electrical industry. The most important is its high level of electrical conductivity which has established electrolytic copper, C110, as the industry standard.

High Heat Transfer Qualities:
The ability of coppermetals to transfer heat readily was noted centuries ago. In the past, coppermetals were a preferred material for cooking utensils. Copper and copper alloys are currently still being used in modern copper-clad stainless steel cookware, flatware and utensils. More important, copper has found significant markets in heating and cooling applications such as the radiator and in air-conditioning and refrigeration equipment.

Good Strength:
The mechanical strength of coppermetals is determined by composition, cold reduction, and heat treatment, but is modified by the temperature at which the metals are used. Since coppermetals by themselves are strong for most applications without additional reinforcements, they are adaptable to a wide variety of uses where advantage can be taken of their other characteristics.

Fine Spring Qualities:
Coppermetals are remarkably resistant to fatigue under temperatures ranging from 300 degrees to -300 degrees Fahrenheit. When this spring ability is combined with other coppermetal characteristics as listed above, the result is a material that is hightly adaptable for a wide range of products.

Excellent Machinability:
The ease with which coppermetals can be machined makes it possible to produce small parts more economically from them than from most other materials. The best coppermetal for this purpose is free-cutting brass (alloy 360), which has been chosen as the standard for machinability. Alloy 360, like other copper alloys with high machinability, contains lead. Lead does not dissolve in the copper alloys, but instead remains finely dispersed throughout the metal and serves as a lubricant for the cutting tool.

Ease of Joining:
Coppermetals are readily adapted to a great variety of joining methods. For example, copper roofing joints can be made by folding one sheet over another to form a watertight joint without the use of any other joining means. Other joining methods employed include soldering, brazing, welding, riveting and bonding. Soldering is by far the most common of these methods. Pure tin and solder coatings can be provided as pre-coat or added at the joining process.

Ease of Workability:
One of the reasons why coppermetals are used for many different parts and components is the ease with which they can be formed into desired contours. Suitable alloys are available for almost any type of forming operation, including rolling, bending, drawing, spinning, stamping, coining, hammering and forging.

Resistance to Fatigue, Abrasion and Wear:
Coppermetals have the rare property of being resistant to fatigue, abrasion and wear. This resistance to abrasion and wear has made coppermetals a desirable material for a wide range of surface contacts, such as circular and flat bearings, sliding lock bolts, wear plates and highly leaded bushings.

Superior Properties at Cryogenic Temperatures:
Coppermetals do not become embrittled in sub-zero temperatures as low as -300 degrees F. In fact, at these temperatures the alloys have improved ductability and strength. As a result, coppermetals have become quite a valuable for the new science of cryogenics and for use in space vehicles.

Non-Magnetic Properties:
Most coppermetals are non-magnetic, which is desirable when it is necessary that the influence of magnetic currents in a material is to be avoided. This property is especially important in many electronic applications as well as housings for magnetic instruments.

Non-Sparking Properties:
Products and tools which are used near explosives and volatile fuels that could explode from a spark are commonly made of non-sparking coppermetals.

Beauty and Color Range:
Copper and its alloys are the only commercial metals which can be produced in colors, other than white or gray. Consequently, their natural colors are frequently desired. The color range is quite wide and can be accurately matched at a later time. This is important in large scale assembly line production where color match from different suppliers at different times is necessary. The natural color of copper is reddish, but varying the amount of zinc and/or nickel changes the color markedly from yellow, pink and gold, to silver. Coppermetals are noted for their coloration, which is the result of aging in the atmosphere. The green and bronze colored oxidation can not be duplicated chemically, although some surface colors can be produced by chemical means. Colors of coppermetal ranging from chocolate to pale green are highly preferred for architectural effects.

Harmonic Vibration:
The use of copper and bronze bells dates from ancient times. Small bells were fashioned for cattle and larger bells were made for temples and public buildings. Coppermetals are preferred whenever the pitch of the harmonic vibration must be controlled for the production of a particular sound, whether the applied force is direct, as in the case of the bell, or indirect, as in the case of a horn.

High Scrap Value:
Copper is one of the highest priced commercial metals. Because of their durability, coppermetals retain a high degree of value, even in scrap form. Approximately 40% of all U.S. consumption of copper comes from secondary metal. Very little copper scrap is ever totally destroyed. Scrap returns to the furnaces in various cycles. The quickest form of scrap return is that generated by the mills themselves and is termed "mill run-around scrap".