CAC402 / C90300 Cast Phosphor Bronze: A High-Performance Material

CAC402 / C90300 Cast Phosphor Bronze: A High-Performance Material

CAC402 / C90300 cast phosphor bronze is a material with excellent properties, making it exceptionally well-suited for bearings, bushings, and other high-load mechanical components. JIS BC2 Grade Cast Bronze Bearing and Plate, CAC402 / C90300, JIS/ASTM

Summary of Key Characteristics of CAC402 / C90300

The popularity of this material is primarily due to the following properties:

• Excellent Wear Resistance: This allows it to perform exceptionally well in high-friction environments, effectively extending the service life of components and reducing maintenance costs associated with wear.

• Good Corrosion Resistance: Its strong resistance to corrosion, particularly in aqueous or mixed-lubrication environments, makes it an ideal choice. It effectively prevents degradation, ensuring the long-term operational stability of components.

• High Strength and Toughness: This combination enables it to withstand heavy loads and resist fracture or deformation, ensuring the reliability of mechanical components under demanding conditions.

• Excellent Castability: Its superior castability allows manufacturers to easily produce complex shapes, offering significant flexibility in design and production and facilitating the creation of optimized component structures.

Typical Applications

As noted, C90300 cast phosphor bronze is widely used for components requiring wear resistance and high load-bearing capacity, such as:

• Bearings

• Bushings

• Gears

• Valves

Chemical Composition Overview

Its chemical composition underpins these excellent properties:

• Copper (Cu): Approx. 85%

• Tin (Sn): 5-7%

• Phosphorus (P): 0.03-0.35%

• Remainder: Manganese, Iron, and other trace elements

In summary, CAC402 / C90300 is a highly reliable and versatile cast copper alloy, making it an ideal choice for manufacturing high-performance, durable mechanical components.

Understanding JIS BC2 Grade Cast Bronze

BC2 is a grade of cast tin bronze specified under the Japanese Industrial Standard (JIS) H 5120. It is a highly versatile and widely used alloy known for its balanced combination of mechanical properties, corrosion resistance, and excellent castability. It is often considered a “workhorse” general-purpose bronze.

Key Characteristics of BC2

• Good Strength and Hardness: Provides reliable performance for general-purpose mechanical parts.

• Excellent Wear Resistance: Suitable for moderate-load bearings and sliding components.

• Good Corrosion Resistance: Performs well in seawater and various industrial environments.

• Excellent Pressure Tightness: This makes it an ideal material for valves, pump bodies, and hydraulic components that must contain fluids under pressure without leaking.

• Good Machinability: The presence of lead and zinc in its composition improves its machinability, making it easier to finish into final parts.

Chemical Composition (JIS H 5120)

The composition of BC2 is slightly different from the C90300 you mentioned earlier, notably with the intentional addition of zinc and lead.

Typical Applications

Due to its balanced properties, BC2 is used in a wide range of applications:

• Valves and Fittings: Valve bodies, flanges, and pipe fittings.

• Pump Components: Pump casings, impellers, and pressure-retaining parts.

• Bearings and Bushings: For low-to-moderate speed and load applications.

• General Machinery Parts: Gears, nuts, and other structural components.

• Water Meters and Plumbing Fixtures.

Comparison and International Equivalents

This is a crucial point. JIS BC2 is considered a very close equivalent to the American standard ASTM C90300 (CDA 903), which we discussed previously. They are often used interchangeably.

Here is a clear comparison table:

Summary: BC2 vs C90300

• BC2 (JIS) and C90300 (ASTM) are essentially direct counterparts.

• The primary difference from the purer phosphor bronze (like C92200 or CuSn12) is the intentional addition of Zinc (Zn) and Lead (Pb).

  • Zinc improves castability and makes the material more cost-effective.

  • Lead significantly improves machinability.

In essence, BC2 is a highly reliable, general-purpose cast tin bronze (often called a leaded gunmetal) that is specified under the Japanese JIS standard. It is functionally equivalent to the American C90300 for most engineering applications.

Equivalence of C90300 to European Standard CuSn6/CuSn6.5

Your point about C90300 phosphor bronze corresponding to the European standards CuSn6 or CuSn6.5 is a crucial and practical observation. These materials are highly similar in many respects, making them interchangeable in international applications.

Key Similarities:

• Similar Chemical Composition: The primary components of C90300 are approximately 85% copper, 5-7% tin, and a small amount of phosphorus. This composition is very close to that of CuSn6 or CuSn6.5 (copper-tin alloys with 6% or 6.5% tin content). Tin is the key element for enhancing the hardness, strength, and wear resistance of bronze, while phosphorus further improves its castability and wear resistance.

• Matching Performance Characteristics: Both materials exhibit excellent wear resistance, corrosion resistance, and outstanding mechanical properties. This makes them ideal for manufacturing bearings, bushings, and other mechanical parts that must withstand high loads and friction. Whether in high-friction environments or in water and other lubricating media, both materials demonstrate excellent durability.

• Overlapping Application Areas: Due to their highly similar properties, C90300 and CuSn6/CuSn6.5 have extensive overlap in industrial applications. They are the preferred materials for a wide range of high-load mechanical transmission components.

European Standard:

You mentioned that CuSn6 (or CuSn6.5) conforms to EN 1982, which is the general European standard for cast copper alloys. This means that when procuring or specifying this type of material in the European market, the EN 1982 standard is referenced to ensure the material’s quality and performance meet the required specifications.