These are basically alloys of copper, tin and zinc. They are the true bronzes. Tin and zinc added to copper greatly increase its strength and hardness. Phosphorus and lead are also sometimes added to the tin bronzes: phosphorus to further increase hardness; lead to improve machinability. All of the Tin Bronzes and leaded tin bronzes are characterized by a good combination of physical properties and exceptional corrosion resistance. They are used in naval construction and are considered among the best valve and pump bronzes.

Alloy C90500/Ingot#210 Commonly referred to as Gunmetal is a good corrosion and wear resistant alloy used typically for Bearings, pump impellers, steam fittings, gears, piston rings, pump bodies, valve components.

Alloy C90700/Ingot#205 Phos. Gear Bronze excellent resistance to both wear and corrosion and is usually specified for use as special bearings, pump parts, gears and steam fittings.

Alloy C92200/Ingot#245 also known as Navy "M" is used for high quality valves, fittings and other pressure vessel applications operating at temperatures up to 550F (290C) is also used for gears, bearings and bushings.

Alloy C92600/Ingot#215 Strong general utility structural bronze for use under severe conditions, steam pressure castings, high pressure valves and pipe fittings, pump pistons, bolts, nuts, and gears.

Nominal Chemical Composition & Typical Properties

The red brasses and semi-red brasses are the most widely used of all copper base casting alloys. These alloys offer an excellent combination of corrosion resistance, machinability, moderate strength, and foundry characteristics. In this group of alloys, tin and zinc are alloyed with copper to add strength. Lead is added to improve Machinability. Most red brasses and semi-red brasses are comparatively low in cost.

Alloy C83600/Ingot #115 is used for valves, pipe fittings, water pump and meter housings, impellers, small gears, high quality plumbing goods, statuary and plaques, and marine applications. These applications are possible due to the corrosion resistance, machinability, strength, bearing properties, color and excellent castability of the alloy.

Alloy C84400/Ingot #123 is used for general hardware fittings, ornamental castings, commercial plumbing fixtures, and certain low-pressure valves and fittings.

Nominal Chemical Composition & Typical Properties

These alloys are traditionally the bearing and bushing bronzes. The copper-tin forms the load-bearing matrix: the lead is present as well-distributed particles, which provide embeddability, lubrication under load, and ease of machining. By varying the relative proportions of tin and lead in high-leaded tin bronze, it is possible to design a family of alloys that can be used over a wide range of conditions. For example, the high-tin, low-lead alloys will tolerate high loads and high speeds while the higher lead alloys are usually used for high load and low-speed service. In applications where shaft alignment or shaft wear is a problem, the leaded tin bronzes are often the most satisfactory materials to use. They have the malleability to adapt to changing conditions; they will transfer heat sufficiently to run cool; and they will stand up for long periods of time without adequate lubrication.

Alloy C93200/Ingot#315 is the general-utility alloy of this family and finds use in general bearing and bushing applications.

Alloy C93700/Ingot#305 Because of its higher tin and lead contents, is suitable for bearings involving high speed and heavy pressures, as well as pump and impeller parts requiring corrosion resistance and strength.

Alloy C93800/Ingot#319 is also used for larger bearings, but for less demanding service involving only moderate pressures. The material is also commonly used for pump parts in acid mine waters.

Nominal Chemical Composition & Typical Properties

These casting alloys are made by basically adding silicon to copper. They have generally excellent qualities; corrosion resistance equal to that of copper, and a wide range of desirable physical characteristics.

Alloy C87200/Ingot#500 (Silicon Bronze) Typical applications are pump and valve parts, impellers, bearings, gears, marine fittings, bells, statuary, and art casting.

Alloy C87500/Ingot#500 (Silicon Brass) applications include bearings, gears, impellers, valve stems, rocker arms, small boat propellers.

Nominal Chemical Composition & Typical Properties

Manganese Bronzes are the strongest of all copper-base alloys in the as cast condition. The term "manganese bronze" is inaccurate and somewhat confusing, since some alloys in this category actually contain very little manganese. For this reason, these alloys are more properly called high-strength yellow brasses. Manganese Bronze alloys find applications where relatively high strength is required in combination with exceptional corrosion resistance and moderate cost. Manganese Bronze is an alloy of copper and zinc to which aluminum, iron, manganese and sometimes nickel or tin have been added. Aluminum is the principal strengthening element and may be present from 0.75% to 7.5%.

Alloy C86500/Ingot#421 (Mag70) This alloy has somewhat better corrosion resistance than alloy C86200 & C86300 and is used for parts requiring strength and toughness. Typical applications include gears, valve stems, lever arms, liners, and marine fittings.

Alloy C86200/Ingot#423 (Mag90) Applications for this alloy include structural castings, heavy-duty bearings, hold down nuts, gears, etc.

Alloy C86300/Ingot#424 (Mag110) Extra heavy duty high strength alloy, typical uses for this alloy include slow speed heavy load bearings, gears, cams, screw down nuts, and hydraulic cylinder parts.

Nominal Chemical Composition & Typical Properties

Aluminum bronze alloys offer high strength and, hardness, excellent corrosion resistance, good wearing qualities, good fatigue resistance, and are well suited for service at elevated temperatures. The properties of alloys within certain composition ranges can be improved further by heat treatment. The addition of aluminum, about 6% to 12%, and varying amounts of iron, nickel, manganese and/or silicon alloying additions provide a broad range of mechanical properties; from high ductility (as in the tin bronzes) to the high-strength levels of high-tensile manganese bronze. Aluminum bronzes are widely used in applications where good strength, hardness, ductility and corrosion resistance is required. Because of their unusual range of properties, aluminum bronzes are used for special engineering applications such as dies, valve seats, slides, worm gears, cams, screw-down nuts, and non-sparking safety tools.

Alloy C95400/Ingot#415 9C Typical uses include pump impellers, bearings, gears, worms, bushings, valve seats, non-sparking tools, valve and pump bodies. This alloy is not suitable for exposure to oxidizing acids.

Alloy C95500/Ingot#415 9D This alloy is used for corrosion resistant structural parts, bushings, gears, pickling hooks, agitators, pump parts, dies and wear parts, not suitable for use in strong oxidizing acids.

Alloy C95800/Ingot#415 Typical uses for this alloy include propeller blades and hubs for fresh and sea water service, structural applications, gears and worm wheels.

Nominal Chemical Composition & Typical Properties

The applications for aluminum alloys are almost limitless. Choosing an Aluminum alloy for a particular application depends on many factors. Some considerations that should be taken into account are:

1. Foundry characteristics for the casting process that will be used;
2. Required mechanical and other properties for the service intended;
3. Mechanical properties over the service life;
4. Corrosion resistance for the application;
5. Machinability, pressure tightness and finishability, if necessary;

Another consideration that should be taken into account is the finished cost of the part. The following among many other variables can directly affect the cost:

1. The alloy chosen and the technical requirements of casting that alloy;
2. Quantity of castings to be produced;
3. Process used;
4. Complexity of the shape of the part;
5. The tooling used for producing the molds;
6. Dimensional tolerances required;
7. Inspection and quality standards required

Common Aluminum Alloys we pour at Bergstrom Foundry:

Typical Mechanical Properties

In many instances the zinc-aluminum alloys offer major performance and cost benefits over cast iron, aluminum, and bronze, offering new opportunities to designers. Zinc Aluminum alloys offer tensile strengths competitive with cast iron (class 30) and superior to those of bronze, brass and aluminum. These alloys show superior hardness over bronze and aluminum, usually resulting in improved wear characteristics. ZA-12 and ZA-27 are extremely resistant to galling, and have natural lubricity. They are well suited for moderate to high load, slow speed bearing and bushing applications running below 200 degrees F. ZA-12 and ZA-27, as cast can handle repeated or cyclic stress levels up to approximately 15KPSI and 25KPSI respectively. Typical applications include; machine parts, fluid and pressure applications, electrical conduit fittings, transportation components, decorative applications.

1. Casting Copper-Base Alloys, American Foundrymen's Society; Des Plaines, Illinois
2. Lavingot, R. Lavin & Sons, Inc.; Chicago, Ill
3. Colonial Metals Co., Columbia, PA.
4. Guide to Copper Casting Alloys, Federated Metals; New York, N.Y.
5. Brass & Bronze Casting Alloys, Federated Metals; New York, N.Y.
6. Aluminum Casting Technology-2^nd Edition, American Foundrymen's Society; Des Plaines, Illinois
7. Zinc Casting Alloys, Kidd Creek Mines Ltd.,

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