Tin Bronze – Materials and norms

CuSn3Pb7Zn9 (also Rg3) is characterized by excellent mechanical properties and resistance to wear and corrosion. This alloy contains approximately 3% tin, 7% lead, and 9% zinc, combining strength, wear and corrosion resistance, and machinability. Its tensile strength ranges between 180–220 MPa and hardness reaches 60–70 HB, ensuring reliable performance even in demanding operating conditions. CuSn3Pb7Zn9 is suitable for manufacturing components exposed to high mechanical stress and requiring long-term durability: valves, pumps, plain bearings, marine shafts, gears, and electrical contacts.

CC490K, also known as CuSn3Zn8Pb5-C, is a leaded gunmetal alloy widely recognized for its excellent machinability, good corrosion resistance, and reasonable strength. This alloy is particularly suitable for applications requiring moderate mechanical loads and non-critical engineering uses. CC490K is commonly utilized in the manufacturing of valve bodies, pump components, general hardware, ornamental castings, plumbing supplies, and fixtures. Its good wear resistance and ability to operate effectively in environments up to 200°C make it suitable for light-duty bearings and low-pressure valves and fittings.

CuSn5Zn5Pb2, also designated as CC499K, is a leaded tin bronze alloy notable for its excellent machinability, good corrosion resistance, and moderate strength. CuSn5Zn5Pb2-C (CC499K) is suitable for applications requiring good wear resistance and machinability, such as bearings, bushings, and various components in the automotive and general engineering industries. Its balanced composition provides versatility for various casting processes, including sand casting, permanent mold casting, centrifugal casting, and continuous casting.

CuSn5Zn5Pb5 (CC491K; formerly Rg5, also CuSn5ZnPb5) can be classified somewhere between tin and lead bronze and it is also known under the name Rg5 or as red bronze. This alloy has good casting, machining and soldering properties. It is used in production of normal duty pump housings, water or steam fittings, low-pressure valves, gate valves, small gears, thin-walled castings, bushings, grommets, bearings,  pipe fittings, gasoline and oil-line fittings, fire extinguishing equipment fitting, etc.

CuSn6 (CW452K) offers an excellent combination of strength, hardness and cold formability. This alloy also has good corrosion and wear resistance, and soldering properties. Typical applications include:

• Electrical contacts and connectors: Used in switches, relays, and terminals due to its good conductivity and mechanical properties.
• Springs and diaphragms: Ideal for dynamically loaded components, providing good elasticity and fatigue resistance.
• Sliding bearings and bushings: Suitable for medium-load applications requiring good wear resistance.
• Gears and worm wheels: Used in low-friction environments where high strength and durability are needed.
• Marine and offshore equipment: Offers excellent corrosion resistance in saltwater conditions.
• Automotive and aerospace components: Commonly used in precision parts that require high mechanical strength and stability.
• CuSn6 (CW452K) is also used for tubes where flexibility is needed (e.g. as a Bourdoun tube in pressure gauges), in small metal products, metal fabric, wires, fasteners, and knives for paper mills.

CuSn6Zn4Pb2-C (CC498K) is a high-performance tin bronze alloy known for its excellent wear resistance, good machinability, and corrosion resistance. Its composition includes tin (Sn) for strength and wear resistance, zinc (Zn) for improved mechanical properties, and lead (Pb) for enhanced machinability and self-lubricating properties. This makes it particularly well-suited for applications requiring high load-bearing capacity and resistance to friction. Typical uses of CuSn6Zn4Pb2-C include bushings, bearings, and sliding components in heavy machinery, worm gears and thrust washers in gear systems, and pump and valve components in marine, hydraulic, and chemical industries. Its corrosion resistance also makes it ideal for shipbuilding, propeller hubs and rudders, water treatment systems, and offshore applications where exposure to aggressive environments is common.

CuSn7Zn2Pb3-C (CC492K) is a leaded tin bronze alloy with a balanced composition of 7% tin (Sn), 2% zinc (Zn), and 3% lead (Pb), providing excellent wear resistance, good machinability, and self-lubricating properties. The presence of lead (Pb) enhances its sliding properties, making it particularly suitable for applications requiring low friction and high load-bearing capacity. 

Typical applications include:

• Bearings and bushings: Used in heavy machinery and industrial equipment for their ability to withstand friction and wear (especially in moderate load and speed).
• Worm gears and thrust washers: Common in gear systems and power transmission components, where durability is essential.
• Hydraulic and steam fittings: Ideal for pressurised systems requiring high mechanical strength and corrosion resistance.
• Pump components (impellers and housings,), valve components, and pipe fittings: Used in marine, chemical, and water treatment industries, thanks to its corrosion resistance and good sealing properties.
• Sliding elements and guide rails: Suitable for applications with high surface pressures and sliding speeds, ensuring long service life.

CuSn7Zn4Pb3 is equivalent to CuSn7Zn2Pb3-C (CC492K). CuSn7Zn4Pb3 is a leaded tin bronze alloy with a balanced composition of 7% tin (Sn), 4% zinc (Zn), and 3% lead (Pb), providing excellent wear resistance, good machinability, and self-lubricating properties. The presence of lead (Pb) enhances its sliding properties, making it particularly suitable for applications requiring low friction and high load-bearing capacity. 

Typical applications include:

• Bearings and bushings: Used in heavy machinery and industrial equipment for their ability to withstand friction and wear (especially in moderate load and speed).
• Worm gears and thrust washers: Common in gear systems and power transmission components, where durability is essential.
• Hydraulic and steam fittings: Ideal for pressurised systems requiring high mechanical strength and corrosion resistance.
• Pump components (impellers and housings,), valve components, and pipe fittings: Used in marine, chemical, and water treatment industries, thanks to its corrosion resistance and good sealing properties.
• Sliding elements and guide rails: Suitable for applications with high surface pressures and sliding speeds, ensuring long service life.

CuSn7Zn4Pb7 (CuSn7ZnPb; CC493K) can be classified somewhere between tin and lead bronze and it is also known under the trivial name Rg7 or as red bronze. It is one of the most popular bronze alloys because it can be used in various machine parts. CuSn7Zn4Pb7 is a medium-hardness material and it works well under emergency conditions. It has very good machining, welding and soldering properties. Typical applications include:

• Bearings and bushings: Ideal for heavy-load applications in hydraulic systems, construction machinery, and industrial equipment.
• Worm gears and thrust washers: Used in gear systems and power transmission where friction reduction is essential.
• Pump and valve components: Common in marine, chemical, and water treatment industries, offering excellent corrosion resistance and sealing properties.
• Hydraulic and steam fittings: Ideal for pressurized systems requiring high mechanical strength and corrosion resistance.
• Guide rails and sliding elements: Perfect for high-pressure, slow-moving applications, reducing wear and extending service life.
• Plain bearings in automotive and railway industries: Ensures smooth operation under variable loads and lubrication conditions.
• Also medium-load sliding plates and rails, piston pin bushings, connecting rods, gears...

CuSn8 (CW453K) is a high-tin bronze alloy with 8% tin (Sn), known for its high strength, excellent wear resistance, good corrosion resistance, and good sliding properties. Typical applications include:

• Bearings and bushings: Used in high-load, low-speed applications, such as construction and agricultural machinery.
• Springs and connectors: Common in electrical and mechanical applications requiring good elasticity and fatigue resistance.
• Sliding elements and wear plates_ Ideal for guide rails, thrust washers, and other tribological applications.
• Gears and worm wheels: Provides good load-bearing capacity in high-friction environments.
• Shipbuilding and offshore equipment: Offers excellent corrosion resistance in saltwater environments.
• Aerospace and automotive application: Used in precision parts requiring high strength and fatigue resistance.
• It is also used in production of springs, bolts, couplings, connectors, fuses, paper net warps, art objects, etc.

CuSn8P (CC459K) is a bronze alloy with a high tin content (8%) and the addition of phosphorus, known for its high strength, excellent wear resistance, good corrosion resistance, and good sliding properties. CuSn8P (CC459K) is suitable for components requiring high fatigue strength, elasticity, and excellent formability. Typical applications include:

• Bearings and bushings: Used in high-load and low-speed components such as construction and agricultural machinery. 
• Springs and connectors: Common in electrical and mechanical applications requiring good ductility and wear resistance. 
• Sliding elements and wear plates: Ideal for guide rails, axial washers, and other tribological applications.
•  Gears and worm wheels: Provide good durability in high-friction environments. 
• Shipbuilding and offshore equipment: Offers excellent corrosion resistance in saltwater environments. 
• Aerospace and automotive applications: Used in precision parts requiring high strength and wear resistance.
• CuSn8P is also used to manufacture springs, bolts, couplings, connectors, fuses, paper mill screens, and artistic objects.

CuSn10 (CC480K) is a high-tin bronze alloy with 10% tin (Sn), known for its exceptional strength, wear resistance, and corrosion resistance, particularly in marine and industrial environments. This lead-free alloy is highly durable (higher than CuSn8) and performs well under high loads and frictional stress (up to 300°C), making it ideal for applications where lubrication is limited or environmental regulations restrict lead usage, such as:

• Bearings and bushings: Used in heavy-duty machinery and industrial equipment, providing excellent wear resistance.
• Gears and worm wheels: Suitable for power transmission applications, offering good load-bearing capacity.
• Pump and valve components: Common in marine, chemical, and water treatment industries, thanks to high corrosion resistance.
• Hydraulic and steam fittings: Ideal for pressurised systems that require high strength and thermal resistance.
• Sliding elements and wear plates: Used in guide rails and thrust washers, ensuring long service life under frictional conditions.
• Shipbuilding and offshore structures: Resistant to seawater corrosion, making it suitable for propellers, shafts, and marine hardware.
• Also: impellers in pumps, clamping (pressure) nuts, plain bearings of machine tools and gearboxes, components for chemical appliances or centrifuges

CuSn10Zn2 (CuSn10Zn) resists hard water well, so it is used in plain bearings and couplings that are not exposed to another high loads. Historically, this alloy was called Rg10.

CuSn11P (CC481K) is a phosphor bronze alloy with 11% tin (Sn) and phosphorus (P), known for its exceptional strength, wear resistance, and excellent corrosion resistance, particularly in marine and industrial environments. The addition of phosphorus enhances hardness, improves wear resistance, and refines the grain structure, making it ideal for high-load, high-wear applications. This lead-free alloy is widely used where environmental regulations restrict lead-containing materials. Typical applications of CuSn11P (CC481K) include:

• Heavy-duty bearings and bushings: Used in industrial machinery, hydraulic systems, and construction equipment due to its high load-bearing capacity.
• Gears and worm wheels: Suitable for power transmission components, providing excellent wear resistance under high stress.
• Pump and valve components: Common in marine, chemical, and water treatment industries, offering superior corrosion resistance.
• Sliding elements and wear plates: Ideal for guide rails, thrust washers, and friction-intensive applications.
• Shipbuilding and offshore equipment: Resistant to seawater corrosion, making it ideal for marine propellers, shafts, and submerged components.
• High-performance mechanical parts: Used in aerospace, railway, and automotive industries, where durability and reliability are crucial.
• Sliding elements and wear plates: Used in guide rails and thrust washers, ensuring long service life under frictional conditions.

CuSn11Pb2 (CC482K, formerly Rg3) is a leaded tin bronze alloy with 11% tin (Sn) and 2% lead (Pb), offering high strength, excellent wear resistance, and superior corrosion resistance, particularly in marine and industrial environments. The tin content provides mechanical strength and hardness, while the lead content enhances machinability and self-lubricating properties, making it ideal for heavy-load, high-friction applications. Typical applications of CuSn11Pb2 (CC482K) include:

• Bearings and bushings: Used in heavy-duty machinery, hydraulic systems, and construction equipment, ensuring low friction and wear resistance.
• Gears and worm wheels: Suitable for power transmission components, offering excellent load-bearing capacity.
• Pump and valve components: Common in marine, chemical, and water treatment industries, thanks to its superior corrosion resistance.
• Sliding elements and wear plates: Ideal for guide rails, thrust washers, and friction-intensive applications, ensuring long service life.
• Shipbuilding and offshore equipment: Resistant to seawater corrosion, making it suitable for propellers, shafts, and marine hardware.
• Steam and hydraulic fittings: Used in pressurised systems requiring high mechanical strength and thermal resistance.

CuSn12 (CC483K) alloy is characterized by strength, hardness and high resistance to corrosion, impacts and cavitation. It therefore works well in components that are exposed to heavy loads, friction and pressure. Typical applications of CuSn12 (CC483K) include:

• Bearings and bushings: Used in heavy-duty industrial machinery and hydraulic systems, providing high wear resistance.
• Gears and worm wheels: Suitable for power transmission applications, ensuring low friction and long service life.
• Pump and valve components: Common in marine, chemical, and water treatment industries, offering superior corrosion resistance.
• Sliding elements and wear plates: Ideal for guide rails, thrust washers, and friction-intensive applications.
• Shipbuilding and offshore equipment: Resistant to seawater corrosion, making it suitable for propellers, shafts, and submerged components.
• High-load mechanical parts: Used in railway, automotive, and aerospace industries, where durability and reliability are critical.
• Also: gear rings, pressure nuts, impellers and guide wheels, pump seats, bearing shells and linings, flanges....

CuSn12Ni, equivalent to CuSn12Ni2 (CC484K), is a high-tin bronze alloy with 12% tin (Sn) and 2% nickel (Ni), known for its exceptional strength, excellent wear resistance, and superior corrosion resistance, especially in marine and heavy-duty industrial environments. The nickel content enhances mechanical properties, toughness, and resistance to impact and fatigue, making it ideal for applications under high loads and harsh conditions. Typical applications of CuSn12Ni (CC484K) include:

• Heavy-duty bearings and bushings: Used in industrial machinery, hydraulic systems, and construction equipment, ensuring low friction and high wear resistance.
• Gears and worm wheels: Suitable for power transmission applications, providing enhanced durability under extreme conditions.
• Pump and valve components: Common in marine, chemical, and water treatment industries, thanks to excellent corrosion resistance.
• Sliding elements and wear plates: Ideal for guide rails, thrust washers, and high-load applications.
• Shipbuilding and offshore equipment: Resistant to seawater corrosion, making it ideal for propellers, shafts, and submerged components.
• Turbine and energy sector components: Used in hydropower and steam turbine applications where high wear and temperature resistance are required.

CuSn12Ni2 (CC484K) is a high-tin bronze alloy with 12% tin (Sn) and 2% nickel (Ni), known for its exceptional strength, excellent wear resistance, and superior corrosion resistance, especially in marine and heavy-duty industrial environments. The nickel content enhances mechanical properties, toughness, and resistance to impact and fatigue, making it ideal for applications under high loads and harsh conditions. Typical applications of CuSn12Ni2 (CC484K) include:

• Heavy-duty bearings and bushings: Used in industrial machinery, hydraulic systems, and construction equipment, ensuring low friction and high wear resistance.
• Gears and worm wheels: Suitable for power transmission applications, providing enhanced durability under extreme conditions.
• Pump and valve components: Common in marine, chemical, and water treatment industries, thanks to excellent corrosion resistance.
• Sliding elements and wear plates: Ideal for guide rails, thrust washers, and high-load applications.
• Shipbuilding and offshore equipment: Resistant to seawater corrosion, making it ideal for propellers, shafts, and submerged components.
• Turbine and energy sector components: Used in hydropower and steam turbine applications where high wear and temperature resistance are required.

The CuSn14 grade is very similar to CuSn12 (CC483K). It is characterized by strength, hardness, and high resistance to corrosion, impacts, and cavitation. Therefore, it performs very well in components that must withstand heavy loads, friction, and pressure. Typical applications of the CuSn14 alloy include:

• Bearings and bushings: Used in heavy industrial machinery and hydraulic systems, providing high wear resistance. 
• Gears and worm wheels: Suitable for power transmission components, ensuring low friction and long service life. 
• Pump and valve components: Common in marine, chemical, and water treatment industries, offering excellent corrosion resistance. 
• Sliding elements and wear plates: Ideal for guide rails, thrust washers, and friction-intensive applications. 
• Marine industry: Resistant to seawater, making it suitable for propellers, shafts, and submerged components. 
• High-load mechanical parts: Used in the railway, automotive, and aerospace industries, where durability and reliability are crucial. Also: gear rings, pressure nuts, impellers and guide wheels of feeders, pump seats, bearing shells and linings, flanges, or rings.