C3603 Brass

Grade Name

C3603 Lead Brass (Free-Cutting Brass)

Key Features

• Superior Machinability: Lead (1.8–3.7%) enhances cutting efficiency for CNC and automatic lathes.

• High Mechanical Strength: Tensile strength ≥315 MPa (annealed), up to ≥450 MPa (hard state).

• Corrosion Resistance: Stable in dry and freshwater environments; avoid acidic/seawater exposure.

• Eco-Challenges: Complies with RoHS exemptions but faces restrictions due to lead content.

Product Forms & Dimensions

Form	Size Range	Standards
Rod	Diameter 2–300mm, Length 1–12m	JIS H3250-2015
Plate	Thickness 0.5–60mm, Width 100–2000mm	ASTM B36/B36M
Wire	Diameter 0.2–12mm, Coil ≥3kg	JIS H3300-2018
Tube	OD 5–300mm, Wall Thickness 0.5–30mm	EN 12449:1999
Strip	Thickness 0.1–2.5mm, Width ≤250mm	ASTM B134

Chemical Composition

Element	Content (%)	Standard Range
Cu	57.0–61.0	Main Component (JIS H3250)
Zn	Balance	Balance
Pb	1.8–3.7	Enhances Machinability
Fe+Sn	≤0.6	Impurity Control
Impurities	≤1.2	Total Limit

Physical Properties

Property	Value/Description
Density	8.75 g/cm³
Electrical Conductivity	25% IACS (20℃)
Thermal Conductivity	115 W/(m·K)
Thermal Expansion	20×10⁻⁶/℃ (20–300℃)

Mechanical Properties

Condition	Tensile Strength (MPa)	Elongation (%)	Hardness (HRB/HV)
Annealed (O)	≥315	≥15–20	50–65 HRB
Half-Hard (H02)	≥365	≥10	HV≥100
Hard (H)	≥450	≤10	HV≥130

Core Advantages

1. Cost-Effective Machining: Reduced tool wear for mass production.

2. Versatility: Adaptable to cold/hot working and welding.

3. Surface Compatibility: Supports plating and passivation for enhanced durability.

Applications

• Machinery: Gears, valves, bearings, and fasteners.

• Automotive: Radiator components and brake systems.

• Electronics: Connectors and relay housings (with coatings).

• Renewable Energy: Solar collectors and heat exchanger pipes.

Processing Guidelines

• Machining Parameters: Cutting speed 60–120 m/min; avoid 200–600℃ brittleness zone.

• Annealing: 600–700℃ for 1–2 hours to relieve stress.

• Surface Protection: Apply nickel plating or passivation for corrosion resistance.

FAQs

Q1: Differences between C 3603 and C 3600?

A: C3600 has higher Pb (2–3.7% vs. 1.8–3.7%) for better machinability but lower strength.

Q2: Suitability for marine environments?

A: Not recommended for long-term seawater exposure; use protective coatings.

Standards

• JIS H3250-2015: Copper and copper alloy rods.

• ASTM B36/B36M: Brass plates and strips.

• EN 12449:1999: Seamless copper tubes.