BC-6 Bronze (C83600 / JDB 500#S2): The Definitive Guide to Composition, Properties, and Applications

In the world of copper-based alloys, BC-6 Bronze stands out as a versatile, high-reliability material widely used in mechanical engineering. Often referred to by its international standards—C83600 (ASTM) or LG2 (BS)—this material is the go-to solution for components requiring a balance of strength, corrosion resistance, and machinability.

If you are looking for a material for mid-load, low-speed applications such as bearings, bushings, or pump components, understanding the technical specifications of BC-6 Bronze (classified as JDB (500#S2) in modern material codes) is crucial.

What is BC-6 Bronze?

BC-6 Bronze is a Cast Tin Bronze, also known as 5-5-5 Leaded Tin Bronze. The name “5-5-5” refers to its typical composition: approximately 5% Tin (Sn), 5% Zinc (Zn), and 5% Lead (Pb), with the balance being Copper (Cu).

In our Material Correspondence Table, BC-6 falls under the JDB (500#S2) category. It is recognized globally by the following standards:

Key Material Properties

When selecting a material for engineering components, performance parameters are non-negotiable. Based on the JDB (500#S2) specification sheet, here are the critical physical and mechanical properties of BC-6 Bronze:

1. Mechanical Strength

BC-6 Bronze offers a balanced mechanical profile suitable for functional components that are not subject to extreme stress but require reliability.

• Tensile Strength: > 200 N/mm²

• Hardness (HB): > 70 HB

• Elongation: > 10%

While it does not match the raw strength of high-strength alloy copper (like JDB 500# with >750 N/mm²), its elongation rate ensures it can handle vibration and shock absorption without fracturing.

2. Thermal & Physical Properties

• Density: 8.9 g/cm³ (Heavier than aluminum bronze, indicating a high copper content)

• Linear Expansion Coefficient: 1.8 x 10⁻⁵ /℃

• Temperature Limit: -40°C to +400°C

This broad temperature range makes BC-6 suitable for outdoor machinery and environments with moderate temperature fluctuations.

3. Load & Speed Limits

As indicated in the technical data under “Applicable Conditions,” BC-6 is designed specifically for Mid-load, Low-speed scenarios.

• Max Dynamic Load: 60 N/mm²

• Max Linear Speed (Dry): 10 m/min

• Max PV Value: 60 N/mm² * m/min

4. Wear Resistance & Lubrication

One of the standout features of BC-6 Bronze is its compatibility with various lubrication systems. Due to the lead content (Pb), the material itself acts as a solid lubricant to some extent, providing excellent anti-friction properties.

It pairs exceptionally well with Solid Lubricants (such as SL1 or SL4 from the technical data):

• SL1 (Graphite): Offers excellent wear resistance and chemical stability up to 400°C.

• SL4 (PTFE + Additives): Provides the lowest friction coefficient and is ideal for water or seawater lubrication applications (e.g., ships, hydraulic gates).

Global Equivalents and Interchangeability

One of the advantages of choosing BC-6 Bronze is its global standardization. Whether you are sourcing in China, the US, or Europe, you are looking for the same material chemistry:

• USA: ASTM B30-92 C86300? Correction: For BC-6 specifically, the ASTM standard is C83600 (not C86300, which is a high-strength manganese bronze). The table confirms B30-92 C83600.

• Japan: H5112? Correction: The JIS standard for BC-6 is H5111 CAC304 or simply BC6.

• UK: LG2 (BS 1400)

This interchangeability simplifies global procurement and ensures design consistency across international supply chains.

How BC-6 Compares to Other JDB Materials

To understand where BC-6 fits in the material hierarchy, it helps to compare it with other alloys in the JDB series:

As seen above, while JDB (500#) offers higher load capacity, JDB (500#S2) offers better corrosion resistance and lower friction, making it the preferred choice for fluid handling and general machinery where extreme loads are not the primary concern.

Typical Applications

Given its combination of machinability, corrosion resistance, and anti-friction properties, BC-6 Bronze is extensively used in:

1. Bearings and Bushings: Specifically, solid laminated self-lubricating bearings and cylindrical oilless bushings. Its ability to run with minimal lubrication makes it ideal for maintenance-free applications.

2. Pump Components: Impellers, wear rings, and casing parts, especially in water pumps and marine pumps, due to its excellent resistance to seawater corrosion.

3. Valve Components: Valve stems, seats, and guides. The material’s resistance to galling is critical in valve operation.

4. General Machinery: Gears, worm wheels, and piston rings where the operating conditions fall under mid-load, low-speed parameters.

5. Marine Applications: As noted in the SL4 lubricant data, this material is excellent for ships, hydraulic gates, and hydro turbines when paired with water lubrication systems.

Conclusion

BC-6 Bronze (JDB 500#S2 / C83600) remains a cornerstone material for engineers designing reliable, durable components. It strikes the perfect balance between cost-effectiveness, ease of machining, and operational longevity.

While it may not handle the extreme loads of manganese bronze or the high speeds of aluminum bronze, it excels in its niche: mid-load, low-speed applications where corrosion resistance and conformability are key.

Whether you are manufacturing oilless bushings, pump housings, or valve guides, BC-6 Bronze offers a proven, globally standardized solution that delivers consistent performance across a wide range of industrial environments.

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