Ningbo Jintian Copper (Group) Co., Ltd.
Ningbo Jintian Copper (Group) Co., Ltd.
Brass

HPb58-2.5 Brass

Brass

Designation and Standards

  • Standard Brand Name: HPb58-2.5 (Leaded Brass)

  • Applicable Standards: GB/T 5231-2012 (Wrought Brass), GB/T 4423-2007 (Bars)

  • International Equivalent Brand Names: ASTM C37700 (American Standard), JIS C3771 (Japanese Standard)

  • Material Category: Copper-Zinc-Lead Alloy (Cu-Zn-Pb), Copper content 57.0%-60.0%, Lead content 0.8%-1.9%, Zinc balance (about 38%-41%).


Product Features

  • Excellent Machinability:

    The addition of lead significantly improves machinability, making it suitable for precision turning, milling, and other automated machine processing. The surface finish is high, chips are easy to break, and machining efficiency is excellent.

  • Balanced Mechanical Properties:

    Tensile strength ≥440 MPa, with moderate strength and wear resistance. Suitable for cold and hot pressure processing, but poor performance in cold heading or cold stamping.

  • Corrosion Resistance and Limitations:

    Good corrosion resistance in freshwater and dry atmospheric environments, but prone to stress corrosion cracking in sulfur-containing, ammonia, or seawater environments. Corrosion rate is about 0.1-0.15 mm/a.

  • Welding and Processing Adaptability:

    Supports processes like argon protected welding, soldering and brazing, but care should be taken to avoid zinc and lead evaporation, which can lead to pore defects.


Chemical Composition

Element

Cu

Pb

Zn

Fe

Total Impurities

Content (%)

57.0-60.0

0.8-1.9

Balance (about 38%-41%)

≤0.5

≤1.0


Physical Properties

Performance Parameter

Value

Remarks

Density

8.4-8.5 g/cm³

Lightweight design advantage

Melting Point

900-930°C

Moderate casting fluidity

Electrical Conductivity

About 20% IACS

Lower than pure copper, meets general conductivity requirements

Coefficient of Linear Expansion

20.5×10⁻⁶/°C (20-300°C)

Good thermal stability

Thermal Conductivity

105-110 W/(m·K)

Suitable for heat dissipation components


Mechanical Properties

Performance Parameter

Value

Test Condition

Tensile Strength (σb)

≥440 MPa

Strip, room temperature tensile (thickness ≥0.3mm)

Elongation (δ10)

≥5%

Typical value (Y)

Hardness (HB)

75-130

Significant difference depending on processing condition

Annealing Temperature

600-650°C(Conventional Furnace Annealing)

To eliminate cold working hardening

Low-temperature Annealing Temperature

285°C

To relieve internal stress


Common Product Forms and Specifications

Product Form

Specification Range

Application Scenarios

Plate

Thickness 0.2-100mm, Width 305-1000mm

Mechanical connectors, valve blanks

Bar

Diameter 5-120mm, Length 1-6m

Locks, gear blanks

Tube

Outer Diameter 6-530mm, Wall Thickness 0.5-50mm

Marine piping, radiators

Wire

Diameter 1.0-12.7mm

Conductive terminals, precision parts


Core Application Areas

  • Machinery Manufacturing: Valves, bearings, gears (high wear resistance and cutting precision requirements).

  • Shipbuilding Industry: Seawater treatment equipment, radiators (requires protective coatings).

  • Automobile Industry: Engine parts, brake system components (pressure resistance and processing adaptability).

  • Electronics & Electrical: Connectors, switch contacts (balancing electrical conductivity and processing efficiency).


Processing Notes

  • Temperature Control: Hot processing temperature 640-780°C, annealing temperature 600-650°C, avoid lead evaporation.

  • Welding Process: Prefer argon protected welding, soldering and brazing to reduce pore defects.

  • Corrosion Protection: In seawater environments, nickel plating or epoxy resin coatings are required.

  • Environmental Compliance: Lead-containing waste should be treated as hazardous waste to prevent environmental pollution.


Frequently Asked Questions

Q: What is the difference between HPb58-2.5 and HPb59-1?

A: HPb58-2.5 has lower lead content (0.8%-1.9% vs. 1.5%-2.5%) and is more cost-effective, but its machinability is slightly inferior to HPb59-1.


Q: Is it suitable for seawater environments?

A: The corrosion rate is relatively high when exposed directly (0.1-0.15 mm/a); a protective coating or corrosion-resistant alloy should be used.


Q: How to prevent typical failure modes?

A: Low-temperature annealing (285°C) after cold working can eliminate internal stress and prevent stress corrosion cracking.


Standards Reference

  • Chemical Composition and Processing Specifications: GB/T 5231-2012, GB/T 4423-2007.

  • International Standards: ASTM B124 (American standard for bars), JIS H3250 (Japanese standard).


Note: The above data is compiled from national standards and industry technical documents. Actual parameters may vary slightly due to production process differences. Specific details should be based on supplier test reports.


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