bearing bushes bronze brass
bearing bushes bronze brass

CuSn7ZnPb Tin Bronze Bearing Bushing Overview

CuSn7ZnPb Tin Bronze Bearing Bushing

Common Names: Red Bronze, Leaded Gunmetal
Market Status: Most widely used alloy in the market
International Standards: ASTM B505 C93200, RG7 DIN 1705

Key Features

  • Excellent resistance and elongation correlation
  • Semi-hard material with high resistance to wear, corrosion, and seawater
  • Suitable for general-purpose applications

Chemical Composition

Element % Min % Max Notes
Cu (Copper) 81.0 85.0 Includes nickel
Ni (Nickel) – 2.0 –
P (Phosphorus) – 0.10 –
Pb (Lead) 5.0 8.0 –
Sn (Tin) 6.0 8.0 For continuous/centrifugal castings: Min 5.2% Sn, Max 86.0% Cu
Zn (Zinc) 2.0 5.0 –
Al (Aluminum) – 0.01 –
Fe (Iron) – 0.2 –
S (Sulfur) – 0.10 –
Sb (Antimony) – 0.3 –
Si (Silicon) – 0.01 –

Mechanical Properties (Minimum Values)

Property Continuous Casting (GC) Centrifugal Casting (GZ) Notes
Tensile Strength (Rm, MPa) 260 260 For pieces with exterior diameter ≤ 300 mm
Yield Point 0.2% (Rp0.2, MPa) 120 120 –
Elongation 5D (A, %) 12 12 –
Hardness (HBW 10-1000) 70 70 –

Physical Properties

Property Value Unit
Density 8.8 kg/dm³
Specific Heat 0.356 J/(g·K)
Thermal Expansion 18.5 10⁻⁶ K⁻¹
Thermal Conductivity 64 W/(m·K)
Electrical Conductivity 7.5 MS/m

Note:

For continuous and centrifugal castings, the minimum tin content is 5.2%, and the maximum copper content for ingots is 86.0%.

Mechanical properties are valid for pieces with an exterior diameter ≤ 300 mm. For larger sizes, values must be agreed upon with the order.

CuSn7ZnPb Bronze Bearings

CuSn7ZnPb is a type of tin bronze alloy commonly used for bearing bushings and other applications requiring good wear resistance, strength, and anti-frictional properties. Here’s a breakdown of its composition and properties:

  • Composition:

    • Copper (Cu): Base metal, provides good thermal and electrical conductivity, and forms the matrix of the alloy.

    • Tin (Sn): Typically around 7%, enhances strength, hardness, and wear resistance.

    • Zinc (Zn): Improves machinability and corrosion resistance.

    • Lead (Pb): Added in small amounts (usually 1-3%) to improve anti-frictional properties and machinability.

  • Key Properties:

    1. Wear Resistance: Excellent for applications involving sliding or rotating contact.

    2. Strength and Hardness: Suitable for moderate to high-load applications.

    3. Anti-Frictional Properties: Lead content reduces friction, making it ideal for bushings and bearings.

    4. Corrosion Resistance: Good resistance to corrosion, especially in non-acidic environments.

    5. Machinability: Lead and zinc improve the ease of machining.

  • Applications:

    • Bearing Bushings: Widely used in automotive, industrial, and marine applications.

    • Sliding Bearings: Suitable for high-load, low-speed applications.

    • Gears and Sleeves: Used in machinery and equipment requiring durability and low friction.

    • Valve Components: Common in valves and pumps due to corrosion resistance.

Advantages:

  • Long service life under moderate loads.

  • Good compatibility with steel shafts.

  • Relatively low maintenance requirements.

Limitations:

  • Not suitable for extremely high loads or speeds.

  • Lead content may be a concern in certain environmentally sensitive applications.

Alternatives:

  • CuSn12: Higher tin content for increased strength and wear resistance.

  • CuPb10Sn10: Higher lead and tin content for better anti-frictional properties.

  • Aluminum Bronze (e.g., CuAl10Fe5Ni5): For higher strength and corrosion resistance.

If you have specific requirements or operating conditions, let me know, and I can help tailor the material selection further!